Index: /FCKeditor/trunk/_whatsnew.html
===================================================================
--- /FCKeditor/trunk/_whatsnew.html	(revision 1191)
+++ /FCKeditor/trunk/_whatsnew.html	(revision 1192)
@@ -38,4 +38,6 @@
 		New Features and Improvements:</p>
 	<ul>
+		<li>[<a target="_blank" href="http://dev.fckeditor.net/ticket/123">#123</a>] Full support
+			for <strong>document.domain</strong> with automatic domain detection.</li>
 		<li>JavaScript integration file:
 			<ul>
@@ -53,5 +55,6 @@
 		Fixed Bugs:</p>
 	<ul>
-		<li>[<a target="_blank" href="http://dev.fckeditor.net/ticket/681">#339</a>] [<a target="_blank" href="http://dev.fckeditor.net/ticket/681">#681</a>] The SpellerPages
+		<li>[<a target="_blank" href="http://dev.fckeditor.net/ticket/339">#339</a>] [<a
+			target="_blank" href="http://dev.fckeditor.net/ticket/681">#681</a>] The SpellerPages
 			spell checker will now completely ignore the presence of HTML tags in the text.</li>
 	</ul>
Index: /FCKeditor/trunk/editor/_source/classes/fckeditingarea.js
===================================================================
--- /FCKeditor/trunk/editor/_source/classes/fckeditingarea.js	(revision 1191)
+++ /FCKeditor/trunk/editor/_source/classes/fckeditingarea.js	(revision 1192)
@@ -58,17 +58,8 @@
 	if ( this.Mode == FCK_EDITMODE_WYSIWYG )
 	{
-		// Create the editing area IFRAME.
-		var oIFrame = this.IFrame = oTargetDocument.createElement( 'iframe' ) ;
-		
-		// Firefox will render the tables inside the body in Quirks mode if the 
-		// source of the iframe is set to javascript. see #515
-		if ( !FCKBrowserInfo.IsGecko )
-			oIFrame.src = 'javascript:void(0)' ;
-		
-		oIFrame.frameBorder = 0 ;
-		oIFrame.width = oIFrame.height = '100%' ;
-
-		// Append the new IFRAME to the target.
-		eTargetElement.appendChild( oIFrame ) ;
+		// For FF, document.domain must be set only when different, otherwhise
+		// we'll strangely have "Permission denied" issues.
+		if ( FCK_IS_CUSTOM_DOMAIN )
+			html = '<script>document.domain="' + FCK_RUNTIME_DOMAIN + '";</script>' + html ;
 
 		// IE has a bug with the <base> tag... it must have a </base> closer,
@@ -106,4 +97,32 @@
 		}
 
+		// Create the editing area IFRAME.
+		var oIFrame = this.IFrame = oTargetDocument.createElement( 'iframe' ) ;
+
+		oIFrame.frameBorder = 0 ;
+		oIFrame.width = oIFrame.height = '100%' ;
+
+		if ( FCK_IS_CUSTOM_DOMAIN && FCKBrowserInfo.IsIE )
+		{
+			window._FCKHtmlToLoad = html ;
+			oIFrame.src = 'javascript:void( (function(){' +
+				'document.open() ;' +
+				'document.domain="' + document.domain + '" ;' +
+				'document.write( window.parent._FCKHtmlToLoad );' +
+				'document.close() ;' +
+				'window.parent._FCKHtmlToLoad = null ;' +
+				'})() )' ;
+		}
+		else if ( !FCKBrowserInfo.IsGecko )
+		{
+			// Firefox will render the tables inside the body in Quirks mode if the
+			// source of the iframe is set to javascript. see #515
+			oIFrame.src = 'javascript:void(0)' ;
+		}
+
+		// Append the new IFRAME to the target. For IE, it must be done after
+		// setting the "src", to avoid the "secure/unsecure" message under HTTPS.
+		eTargetElement.appendChild( oIFrame ) ;
+
 		// Get the window and document objects used to interact with the newly created IFRAME.
 		this.Window = oIFrame.contentWindow ;
@@ -113,9 +132,12 @@
 		// this.Window.onerror = function() { alert( 'Error!' ) ; return true ; }
 
-		var oDoc = this.Document = this.Window.document ;
-
-		oDoc.open() ;
-		oDoc.write( html ) ;
-		oDoc.close() ;
+		if ( !FCK_IS_CUSTOM_DOMAIN || !FCKBrowserInfo.IsIE )
+		{
+			var oDoc = this.Window.document ;
+
+			oDoc.open() ;
+			oDoc.write( html ) ;
+			oDoc.close() ;
+		}
 
 		// Firefox 1.0.x is buggy... ohh yes... so let's do it two times and it
@@ -127,14 +149,33 @@
 		}
 
-		this.Window._FCKEditingArea = this ;
-
-		// FF 1.0.x is buggy... we must wait a lot to enable editing because
-		// sometimes the content simply disappears, for example when pasting
-		// "bla1!<img src='some_url'>!bla2" in the source and then switching
-		// back to design.
-		if ( FCKBrowserInfo.IsGecko10 )
-			this.Window.setTimeout( FCKEditingArea_CompleteStart, 500 ) ;
+		if ( oIFrame.readyState && oIFrame.readyState != 'completed' )
+		{
+			var editArea = this ;
+			( oIFrame.onreadystatechange = function()
+			{
+				if ( oIFrame.readyState == 'complete' )
+				{
+					oIFrame.onreadystatechange = null ;
+					editArea.Window._FCKEditingArea = editArea ;
+					FCKEditingArea_CompleteStart.call( editArea.Window ) ;
+				}
+			// It happened that IE changed the state to "complete" after the
+			// "if" and before the "onreadystatechange" assignement, making we
+			// lost the event call, so we do a manual call just to be sure.
+			} )() ;	
+		}
 		else
-			FCKEditingArea_CompleteStart.call( this.Window ) ;
+		{
+			this.Window._FCKEditingArea = this ;
+
+			// FF 1.0.x is buggy... we must wait a lot to enable editing because
+			// sometimes the content simply disappears, for example when pasting
+			// "bla1!<img src='some_url'>!bla2" in the source and then switching
+			// back to design.
+			if ( FCKBrowserInfo.IsGecko10 )
+				this.Window.setTimeout( FCKEditingArea_CompleteStart, 500 ) ;
+			else
+				FCKEditingArea_CompleteStart.call( this.Window ) ;
+		}
 	}
 	else
@@ -143,9 +184,9 @@
 		eTextarea.className = 'SourceField' ;
 		eTextarea.dir = 'ltr' ;
-		FCKDomTools.SetElementStyles( eTextarea, 
-			{ 
-				width	: '100%', 
-				height	: '100%', 
-				border	: 'none', 
+		FCKDomTools.SetElementStyles( eTextarea,
+			{
+				width	: '100%',
+				height	: '100%',
+				border	: 'none',
 				resize	: 'none',
 				outline	: 'none'
@@ -171,5 +212,8 @@
 
 	var oEditorArea = this._FCKEditingArea ;
-	
+
+	// Save this reference to be re-used later.
+	oEditorArea.Document = oEditorArea.Window.document ;
+
 	oEditorArea.MakeEditable() ;
 
@@ -215,5 +259,5 @@
 			oDoc.execCommand( 'enableInlineTableEditing', false, !FCKConfig.DisableFFTableHandles ) ;
 		}
-		catch (e) 
+		catch (e)
 		{
 			// In Firefox if the iframe is initially hidden it can't be set to designMode and it raises an exception
@@ -230,10 +274,10 @@
 {
 	var editingArea = evt.currentTarget.contentWindow._FCKEditingArea ;
-	
+
 	// We want to run our function after the events no longer fire, so we can know that it's a stable situation
 	if ( editingArea._timer )
 		window.clearTimeout( editingArea._timer ) ;
 
-	editingArea._timer = FCKTools.SetTimeout( FCKEditingArea_MakeEditableByMutation, 1000, editingArea ) ;	
+	editingArea._timer = FCKTools.SetTimeout( FCKEditingArea_MakeEditableByMutation, 1000, editingArea ) ;
 }
 
Index: /FCKeditor/trunk/editor/_source/classes/fckpanel.js
===================================================================
--- /FCKeditor/trunk/editor/_source/classes/fckpanel.js	(revision 1191)
+++ /FCKeditor/trunk/editor/_source/classes/fckpanel.js	(revision 1192)
@@ -35,7 +35,17 @@
 	if ( FCKBrowserInfo.IsIE )
 	{
+		// This is a trick to IE6 (not IE7). The original domain must be set
+		// before creating the popup, so we are able to take a refence to the
+		// document inside of it, and the set the proper domain for it. (#123)
+		if ( FCK_IS_CUSTOM_DOMAIN )
+			document.domain = FCK_ORIGINAL_DOMAIN ;
+		
 		// Create the Popup that will hold the panel.
 		this._Popup	= this._Window.createPopup() ;
 		oDocument = this.Document = this._Popup.document ;
+
+		// Set the proper domain inside the popup.
+		if ( FCK_IS_CUSTOM_DOMAIN )
+			document.domain = oDocument.domain = FCK_RUNTIME_DOMAIN ;
 
 		FCK.IECleanup.AddItem( this, FCKPanel_Cleanup ) ;
Index: /FCKeditor/trunk/editor/_source/classes/fckxml_gecko.js
===================================================================
--- /FCKeditor/trunk/editor/_source/classes/fckxml_gecko.js	(revision 1191)
+++ /FCKeditor/trunk/editor/_source/classes/fckxml_gecko.js	(revision 1192)
@@ -27,26 +27,41 @@
 	{
 		this.Error = false ;
-		var oFCKXml = this ;
 
+		var oXml ;
 		var oXmlHttp = FCKTools.CreateXmlObject( 'XmlHttp' ) ;
-		oXmlHttp.open( "GET", urlToCall, false ) ;
+		oXmlHttp.open( 'GET', urlToCall, false ) ;
 		oXmlHttp.send( null ) ;
 
 		if ( oXmlHttp.status == 200 || oXmlHttp.status == 304 )
-			this.DOMDocument = oXmlHttp.responseXML ;
+			oXml = oXmlHttp.responseXML ;
 		else if ( oXmlHttp.status == 0 && oXmlHttp.readyState == 4 )
-			this.DOMDocument = oXmlHttp.responseXML ;
+			oXml = oXmlHttp.responseXML ;
 		else
-			this.DOMDocument = null ;
+			oXml = null ;
 
-		if ( this.DOMDocument == null || this.DOMDocument.firstChild == null )
+		if ( oXml )
+		{
+			// Try to access something on it.
+			try
+			{
+				var test = oXml.firstChild ;
+			}
+			catch (e)
+			{
+				// If document.domain has been changed (#123), we'll have a security
+				// error at this point. The workaround here is parsing the responseText:
+				// http://alexander.kirk.at/2006/07/27/firefox-15-xmlhttprequest-reqresponsexml-and-documentdomain/
+				oXml = (new DOMParser()).parseFromString( oXmlHttp.responseText, 'text/xml' ) ;
+			}
+		}
+
+		if ( !oXml || !oXml.firstChild )
 		{
 			this.Error = true ;
-			if (window.confirm( 'Error loading "' + urlToCall + '"\r\nDo you want to see more info?' ) )
-				alert( 'URL requested: "' + urlToCall + '"\r\n' +
-							'Server response:\r\nStatus: ' + oXmlHttp.status + '\r\n' +
-							'Response text:\r\n' + oXmlHttp.responseText ) ;
-
+			if ( window.confirm( 'Error loading "' + urlToCall + '" (HTTP Status: ' + oXmlHttp.status + ').\r\nDo you want to see the server response dump?' ) )
+				alert( oXmlHttp.responseText ) ;
 		}
+		
+		this.DOMDocument = oXml ;
 	},
 
Index: /FCKeditor/trunk/editor/_source/internals/fck.js
===================================================================
--- /FCKeditor/trunk/editor/_source/internals/fck.js	(revision 1191)
+++ /FCKeditor/trunk/editor/_source/internals/fck.js	(revision 1192)
@@ -559,9 +559,4 @@
 	Preview : function()
 	{
-		var iWidth	= FCKConfig.ScreenWidth * 0.8 ;
-		var iHeight	= FCKConfig.ScreenHeight * 0.7 ;
-		var iLeft	= ( FCKConfig.ScreenWidth - iWidth ) / 2 ;
-		var oWindow = window.open( '', null, 'toolbar=yes,location=no,status=yes,menubar=yes,scrollbars=yes,resizable=yes,width=' + iWidth + ',height=' + iHeight + ',left=' + iLeft ) ;
-
 		var sHTML ;
 
@@ -587,6 +582,29 @@
 		}
 
-		oWindow.document.write( sHTML );
-		oWindow.document.close();
+		var iWidth	= FCKConfig.ScreenWidth * 0.8 ;
+		var iHeight	= FCKConfig.ScreenHeight * 0.7 ;
+		var iLeft	= ( FCKConfig.ScreenWidth - iWidth ) / 2 ;
+		
+		var sOpenUrl = '' ;
+		if ( FCK_IS_CUSTOM_DOMAIN && FCKBrowserInfo.IsIE) 
+		{
+			window._FCKHtmlToLoad = sHTML ;
+			sOpenUrl = 'javascript:void( (function(){' +
+				'document.open() ;' +
+				'document.domain="' + document.domain + '" ;' +
+				'document.write( window.opener._FCKHtmlToLoad );' +
+				'document.close() ;' +
+				'window.opener._FCKHtmlToLoad = null ;' +
+				'})() )' ;
+		}
+		
+		var oWindow = window.open( sOpenUrl, null, 'toolbar=yes,location=no,status=yes,menubar=yes,scrollbars=yes,resizable=yes,width=' + iWidth + ',height=' + iHeight + ',left=' + iLeft ) ;
+
+		if ( !FCK_IS_CUSTOM_DOMAIN || !FCKBrowserInfo.IsIE) 
+		{
+			oWindow.document.write( sHTML );
+			oWindow.document.close();
+		}
+
 	},
 
@@ -1143,2 +1161,4 @@
 }
 
+
+
Index: /FCKeditor/trunk/editor/_source/internals/fcktools_gecko.js
===================================================================
--- /FCKeditor/trunk/editor/_source/internals/fcktools_gecko.js	(revision 1191)
+++ /FCKeditor/trunk/editor/_source/internals/fcktools_gecko.js	(revision 1192)
@@ -112,6 +112,38 @@
 		case 'XmlHttp' :
 			return new XMLHttpRequest() ;
+
 		case 'DOMDocument' :
-			return document.implementation.createDocument( '', '', null ) ;
+			// Originaly, we were had the following here:
+			// return document.implementation.createDocument( '', '', null ) ;
+			//
+			// But, when manipulating document.domain (#123), we had
+			// "Permission denied" errors when trying to call methods inside
+			// the returned object. To avoid it, we have to change to the
+			// following, by implementing a "custom" DOM document object, which
+			// includes the methods that are useful for us.
+
+			var domDoc = document.createDocumentFragment() ;
+
+			domDoc.createElement = function( name )
+			{
+				return document.createElement( name ) ;
+			}
+
+			domDoc.createTextNode = function( text )
+			{
+				return document.createTextNode( text ) ;
+			}
+
+			domDoc.createAttribute = function( attName )
+			{
+				return document.createAttribute( attName ) ;
+			}
+
+			domDoc.createComment = function( text )
+			{
+				return document.createComment( text ) ;
+			}
+
+			return domDoc ;
 	}
 	return null ;
@@ -225,5 +257,5 @@
 
 		/*
-		FCKDebug.Output( el.tagName + ":" + "offset=" + el.offsetLeft + "," + el.offsetTop + "  " 
+		FCKDebug.Output( el.tagName + ":" + "offset=" + el.offsetLeft + "," + el.offsetTop + "  "
 				+ "scroll=" + el.scrollLeft + "," + el.scrollTop ) ;
 		*/
Index: /FCKeditor/trunk/editor/_source/internals/fckxhtml.js
===================================================================
--- /FCKeditor/trunk/editor/_source/internals/fckxhtml.js	(revision 1191)
+++ /FCKeditor/trunk/editor/_source/internals/fckxhtml.js	(revision 1192)
@@ -44,5 +44,5 @@
 	// Create the XML DOMDocument object.
 	this.XML = FCKTools.CreateXmlObject( 'DOMDocument' ) ;
-
+	
 	// Add a root element that holds all child nodes.
 	this.MainNode = this.XML.appendChild( this.XML.createElement( 'xhtml' ) ) ;
Index: /FCKeditor/trunk/editor/_source/internals/fckxhtml_gecko.js
===================================================================
--- /FCKeditor/trunk/editor/_source/internals/fckxhtml_gecko.js	(revision 1191)
+++ /FCKeditor/trunk/editor/_source/internals/fckxhtml_gecko.js	(revision 1192)
@@ -25,9 +25,5 @@
 FCKXHtml._GetMainXmlString = function()
 {
-	// Create the XMLSerializer.
-	var oSerializer = new XMLSerializer() ;
-
-	// Return the serialized XML as a string.
-	return oSerializer.serializeToString( this.MainNode ) ;
+	return '<xhtml>' + this.MainNode.innerHTML + '</xhtml>' ;
 }
 
Index: /FCKeditor/trunk/editor/dialog/common/fck_dialog_common.js
===================================================================
--- /FCKeditor/trunk/editor/dialog/common/fck_dialog_common.js	(revision 1191)
+++ /FCKeditor/trunk/editor/dialog/common/fck_dialog_common.js	(revision 1192)
@@ -20,5 +20,38 @@
  *
  * Useful functions used by almost all dialog window pages.
+ * Dialogs should link to this file as the very first script on the page.
  */
+
+// Automatically detect the correct document.domain (#123).
+(function()
+{
+	var d = document.domain ;
+
+	while ( true )
+	{
+		// Test if we can access a parent property.
+		try
+		{
+			var test = window.parent.document.domain ;
+			break ;
+		}
+		catch( e ) {}
+		
+		// Remove a domain part: www.mytest.example.com => mytest.example.com => example.com ...
+		d = d.replace( /.*?(?:\.|$)/, '' ) ;
+
+		if ( d.length == 0 )
+			break ;		// It was not able to detect the domain.
+		
+		try
+		{
+			document.domain = d ;
+		}
+		catch (e) 
+		{
+			break ;
+		}
+	}
+})() ; 
 
 // Gets a element by its Id. Used for shorter coding.
Index: /FCKeditor/trunk/editor/dialog/fck_colorselector.html
===================================================================
--- /FCKeditor/trunk/editor/dialog/fck_colorselector.html	(revision 1191)
+++ /FCKeditor/trunk/editor/dialog/fck_colorselector.html	(revision 1192)
@@ -35,4 +35,5 @@
 			.ColorCell		{ height: 15px ; width: 15px ; }
 		</style>
+		<script src="common/fck_dialog_common.js" type="text/javascript"></script>
 		<script type="text/javascript">
 
@@ -136,6 +137,6 @@
 function Ok()
 {
-	if ( typeof(window.parent.dialogArguments.CustomValue) == 'function' )
-		window.parent.dialogArguments.CustomValue( document.getElementById('selcolor').value ) ;
+	if ( typeof(window.parent.args.CustomValue) == 'function' )
+		window.parent.args.CustomValue( document.getElementById('selcolor').value ) ;
 
 	return true ;
Index: /FCKeditor/trunk/editor/dialog/fck_flash/fck_flash_preview.html
===================================================================
--- /FCKeditor/trunk/editor/dialog/fck_flash/fck_flash_preview.html	(revision 1191)
+++ /FCKeditor/trunk/editor/dialog/fck_flash/fck_flash_preview.html	(revision 1192)
@@ -28,4 +28,5 @@
 		<meta name="robots" content="noindex, nofollow">
 		<link href="../common/fck_dialog_common.css" rel="stylesheet" type="text/css" />
+		<script src="../common/fck_dialog_common.js" type="text/javascript"></script>
 		<script language="javascript">
 
Index: /FCKeditor/trunk/editor/dialog/fck_image/fck_image_preview.html
===================================================================
--- /FCKeditor/trunk/editor/dialog/fck_image/fck_image_preview.html	(revision 1191)
+++ /FCKeditor/trunk/editor/dialog/fck_image/fck_image_preview.html	(revision 1192)
@@ -30,4 +30,5 @@
 	<meta name="robots" content="noindex, nofollow" />
 	<link href="../common/fck_dialog_common.css" rel="stylesheet" type="text/css" />
+	<script src="../common/fck_dialog_common.js" type="text/javascript"></script>
 	<script type="text/javascript">
 
@@ -48,19 +49,21 @@
 </head>
 <body style="color: #000000; background-color: #ffffff">
-	<a id="lnkPreview" onclick="return false;" style="cursor: default">
-		<img id="imgPreview" onload="window.parent.UpdateOriginal();" style="display: none" /></a>Lorem
-	ipsum dolor sit amet, consectetuer adipiscing elit. Maecenas feugiat consequat diam.
-	Maecenas metus. Vivamus diam purus, cursus a, commodo non, facilisis vitae, nulla.
-	Aenean dictum lacinia tortor. Nunc iaculis, nibh non iaculis aliquam, orci felis
-	euismod neque, sed ornare massa mauris sed velit. Nulla pretium mi et risus. Fusce
-	mi pede, tempor id, cursus ac, ullamcorper nec, enim. Sed tortor. Curabitur molestie.
-	Duis velit augue, condimentum at, ultrices a, luctus ut, orci. Donec pellentesque
-	egestas eros. Integer cursus, augue in cursus faucibus, eros pede bibendum sem,
-	in tempus tellus justo quis ligula. Etiam eget tortor. Vestibulum rutrum, est ut
-	placerat elementum, lectus nisl aliquam velit, tempor aliquam eros nunc nonummy
-	metus. In eros metus, gravida a, gravida sed, lobortis id, turpis. Ut ultrices,
-	ipsum at venenatis fringilla, sem nulla lacinia tellus, eget aliquet turpis mauris
-	non enim. Nam turpis. Suspendisse lacinia. Curabitur ac tortor ut ipsum egestas
-	elementum. Nunc imperdiet gravida mauris.
+	<div>
+		<a id="lnkPreview" onclick="return false;" style="cursor: default">
+			<img id="imgPreview" src="javascript:void(0)" onload="window.parent.UpdateOriginal();"
+				style="display: none" alt="" /></a>Lorem ipsum dolor sit amet, consectetuer adipiscing
+		elit. Maecenas feugiat consequat diam. Maecenas metus. Vivamus diam purus, cursus
+		a, commodo non, facilisis vitae, nulla. Aenean dictum lacinia tortor. Nunc iaculis,
+		nibh non iaculis aliquam, orci felis euismod neque, sed ornare massa mauris sed
+		velit. Nulla pretium mi et risus. Fusce mi pede, tempor id, cursus ac, ullamcorper
+		nec, enim. Sed tortor. Curabitur molestie. Duis velit augue, condimentum at, ultrices
+		a, luctus ut, orci. Donec pellentesque egestas eros. Integer cursus, augue in cursus
+		faucibus, eros pede bibendum sem, in tempus tellus justo quis ligula. Etiam eget
+		tortor. Vestibulum rutrum, est ut placerat elementum, lectus nisl aliquam velit,
+		tempor aliquam eros nunc nonummy metus. In eros metus, gravida a, gravida sed, lobortis
+		id, turpis. Ut ultrices, ipsum at venenatis fringilla, sem nulla lacinia tellus,
+		eget aliquet turpis mauris non enim. Nam turpis. Suspendisse lacinia. Curabitur
+		ac tortor ut ipsum egestas elementum. Nunc imperdiet gravida mauris.
+	</div>
 </body>
 </html>
Index: /FCKeditor/trunk/editor/dialog/fck_paste.html
===================================================================
--- /FCKeditor/trunk/editor/dialog/fck_paste.html	(revision 1191)
+++ /FCKeditor/trunk/editor/dialog/fck_paste.html	(revision 1192)
@@ -29,5 +29,5 @@
 	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 	<meta name="robots" content="noindex, nofollow" />
-
+	<script src="common/fck_dialog_common.js" type="text/javascript"></script>
 	<script type="text/javascript">
 var oEditor = window.parent.InnerDialogLoaded() ;
@@ -35,4 +35,5 @@
 var FCKTools	= oEditor.FCKTools ;
 var FCKConfig	= oEditor.FCKConfig ;
+var FCKBrowserInfo = oEditor.FCKBrowserInfo ;
 
 window.onload = function ()
@@ -41,5 +42,5 @@
 	oEditor.FCKLanguageManager.TranslatePage(document) ;
 
-	var sPastingType = window.parent.dialogArguments.CustomValue ;
+	var sPastingType = window.parent.args.CustomValue ;
 
 	if ( sPastingType == 'Word' || sPastingType == 'Security' )
@@ -48,20 +49,38 @@
 			document.getElementById( 'xSecurityMsg' ).style.display = '' ;
 
-		var oFrame = document.getElementById('frmData') ;
-		oFrame.style.display = '' ;
-
-		// Avoid errors if the pasted content has any script that fails: #389
-		var oDoc = oFrame.contentWindow.document ;
-		oDoc.open() ;
-		oDoc.write('<html><head><script>window.onerror = function() { return true ; };<\/script><\/head><body><\/body><\/html>') ;
-		oDoc.close() ;
+		// For document.domain compatibility (#123) we must do all the magic in
+		// the URL for IE.
+		var sFrameUrl = !oEditor.FCK_IS_CUSTOM_DOMAIN || !FCKBrowserInfo.IsIE ? 
+			'javascript:void(0)' :
+			'javascript:void( (function(){' +
+				'document.open() ;' +
+				'document.domain=\'' + document.domain + '\' ;' +
+				'document.write(\'<html><head><script>window.onerror = function() { return true ; };<\/script><\/head><body><\/body><\/html>\') ;' +
+				'document.close() ;' +
+				'document.body.contentEditable = true ;' +
+				'window.focus() ;' +
+				'})() )' ;
+			
+		var eFrameSpace = document.getElementById( 'xFrameSpace' ) ;
+		eFrameSpace.innerHTML = '<iframe id="frmData" src="' + sFrameUrl + '" ' +
+					'height="98%" width="99%" frameborder="0" style="border: #000000 1px; background-color: #ffffff"></iframe>' ;
 		
-		if ( oFrame.contentDocument )
-			oFrame.contentDocument.designMode = 'on' ;
-		else
-			oFrame.contentWindow.document.body.contentEditable = true ;
-
-		// Set the focus on the pasting area
-		oFrame.contentWindow.focus();
+		var oFrame = eFrameSpace.firstChild ;
+
+		if ( !oEditor.FCK_IS_CUSTOM_DOMAIN || !FCKBrowserInfo.IsIE )
+		{
+			// Avoid errors if the pasted content has any script that fails: #389
+			var oDoc = oFrame.contentWindow.document ;
+			oDoc.open() ;
+			oDoc.write('<html><head><script>window.onerror = function() { return true ; };<\/script><\/head><body><\/body><\/html>') ;
+			oDoc.close() ;
+
+			if ( FCKBrowserInfo.IsIE )
+				oDoc.body.contentEditable = true ;
+			else
+				oDoc.designMode = 'on' ;
+
+			oFrame.contentWindow.focus();
+		}
 	}
 	else
@@ -84,5 +103,5 @@
 	var sHtml ;
 
-	var sPastingType = window.parent.dialogArguments.CustomValue ;
+	var sPastingType = window.parent.args.CustomValue ;
 
 	if ( sPastingType == 'Word' || sPastingType == 'Security' )
@@ -307,11 +326,7 @@
 		</tr>
 		<tr>
-			<td valign="top" height="100%" style="border-right: #000000 1px solid; border-top: #000000 1px solid;
-				border-left: #000000 1px solid; border-bottom: #000000 1px solid">
+			<td id="xFrameSpace" valign="top" height="100%" style="border: #000000 1px solid">
 				<textarea id="txtData" cols="80" rows="5" style="border: #000000 1px; display: none;
 					width: 99%; height: 98%"></textarea>
-				<iframe id="frmData" src="javascript:void(0)" height="98%" width="99%" frameborder="0"
-					style="border-right: #000000 1px; border-top: #000000 1px; display: none; border-left: #000000 1px;
-					border-bottom: #000000 1px; background-color: #ffffff"></iframe>
 			</td>
 		</tr>
Index: /FCKeditor/trunk/editor/dialog/fck_smiley.html
===================================================================
--- /FCKeditor/trunk/editor/dialog/fck_smiley.html	(revision 1191)
+++ /FCKeditor/trunk/editor/dialog/fck_smiley.html	(revision 1192)
@@ -34,4 +34,5 @@
 		}
 	</style>
+	<script src="common/fck_dialog_common.js" type="text/javascript"></script>
 	<script type="text/javascript">
 
Index: /FCKeditor/trunk/editor/dialog/fck_specialchar.html
===================================================================
--- /FCKeditor/trunk/editor/dialog/fck_specialchar.html	(revision 1191)
+++ /FCKeditor/trunk/editor/dialog/fck_specialchar.html	(revision 1192)
@@ -34,4 +34,5 @@
 				.Sample { font-size: 24px; }
 		</style>
+		<script src="common/fck_dialog_common.js" type="text/javascript"></script>
 		<script type="text/javascript">
 
Index: /FCKeditor/trunk/editor/dialog/fck_spellerpages.html
===================================================================
--- /FCKeditor/trunk/editor/dialog/fck_spellerpages.html	(revision 1191)
+++ /FCKeditor/trunk/editor/dialog/fck_spellerpages.html	(revision 1192)
@@ -27,4 +27,5 @@
 		<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
 		<meta content="noindex, nofollow" name="robots">
+		<script src="common/fck_dialog_common.js" type="text/javascript"></script>
 		<script src="fck_spellerpages/spellerpages/spellChecker.js"></script>
 		<script type="text/javascript">
Index: /FCKeditor/trunk/editor/fckdialog.html
===================================================================
--- /FCKeditor/trunk/editor/fckdialog.html	(revision 1191)
+++ /FCKeditor/trunk/editor/fckdialog.html	(revision 1192)
@@ -28,20 +28,50 @@
 		<script type="text/javascript">
 
+var args = window.dialogArguments ;
+
+// Automatically detect the correct document.domain (#123).
+(function()
+{
+	var d = document.domain ;
+
+	while ( true )
+	{
+		// Test if we can access a parent property.
+		try
+		{
+			var parentDomain = window.opener ? window.opener.document.domain : args.Editor.document.domain ;
+			
+			if ( document.domain != parentDomain )
+				document.domain = parentDomain ;
+			break ;
+		}
+		catch( e ) {}
+		
+		// Remove a domain part: www.mytest.example.com => mytest.example.com => example.com ...
+		d = d.replace( /.*?(?:\.|$)/, '' ) ;
+
+		if ( d.length == 0 )
+			break ;		// It was not able to detect the domain.
+		
+		document.domain = d ;
+	}
+})() ; 
+
 // On some Gecko browsers (probably over slow connections) the
 // "dialogArguments" are not set so we must get it from the opener window.
-if ( !window.dialogArguments )
-	window.dialogArguments = window.opener.FCKLastDialogInfo ;
+if ( !args )
+	args = window.dialogArguments = window.opener.FCKLastDialogInfo ;
 
 // Sets the Skin CSS
-document.write( '<link href="' + window.dialogArguments.Editor.FCKConfig.SkinPath + 'fck_dialog.css" type="text/css" rel="stylesheet">' ) ;
+document.write( '<link href="' + args.Editor.FCKConfig.SkinPath + 'fck_dialog.css" type="text/css" rel="stylesheet">' ) ;
 
 // Sets the language direction.
-window.document.dir = window.dialogArguments.Editor.FCKLang.Dir ;
+window.document.dir = args.Editor.FCKLang.Dir ;
 
 // IE does not set the window name in showModalDialog(), let's set it here.
-if ( window.dialogArguments.Editor.FCKBrowserInfo.IsIE )
-	window.name = window.dialogArguments.DialogName ;
-
-var sTitle = window.dialogArguments.Title ;
+if ( args.Editor.FCKBrowserInfo.IsIE )
+	window.name = args.DialogName ;
+
+var sTitle = args.Title ;
 document.write( '<title>' + sTitle + '<\/title>' ) ;
 
@@ -52,7 +82,7 @@
 
 	// First of all, translate the dialog box contents.
-	window.dialogArguments.Editor.FCKLanguageManager.TranslatePage( document ) ;
-
-	window.frames["frmMain"].document.location.href = window.dialogArguments.Page ;
+	args.Editor.FCKLanguageManager.TranslatePage( document ) ;
+
+	document.getElementById( 'FrameCell' ).innerHTML = '<iframe id="frmMain" src="' + args.Page + '" name="frmMain" frameborder="0" height="100%" width="100%" scrolling="auto"></iframe>' ;
 }
 
@@ -62,13 +92,13 @@
 
 	// Set the language direction.
-	oInnerDoc.dir = window.dialogArguments.Editor.FCKLang.Dir ;
+	oInnerDoc.dir = args.Editor.FCKLang.Dir ;
 
 	// Sets the Skin CSS.
-	oInnerDoc.write( '<link href="' + window.dialogArguments.Editor.FCKConfig.SkinPath + 'fck_dialog.css" type="text/css" rel="stylesheet">' ) ;
+	oInnerDoc.write( '<link href="' + args.Editor.FCKConfig.SkinPath + 'fck_dialog.css" type="text/css" rel="stylesheet">' ) ;
 
 	SetOnKeyDown( oInnerDoc ) ;
 	DisableContextMenu( oInnerDoc ) ;
 
-	return window.dialogArguments.Editor ;
+	return args.Editor ;
 }
 
@@ -114,5 +144,5 @@
 // Kludge for #1316: Safari seems to have a bug with the time when RefreshSize() is executed - it thinks frmMain's innerHeight 
 // is 0 if we query the value too soon after the page is loaded in some circumstances.
-if ( window.dialogArguments.Editor.FCKBrowserInfo.IsSafari )
+if ( args.Editor.FCKBrowserInfo.IsSafari )
 {
 	window.OriginalRefreshSize = RefreshSize ;
@@ -132,9 +162,9 @@
 function Cancel( dontFireChange )
 {
-	if ( !dontFireChange && !window.dialogArguments.Editor.FCK.EditMode )
+	if ( !dontFireChange && !args.Editor.FCK.EditMode )
 	{
 		// All dialog windows, by default, will fire the "OnSelectionChange"
 		// event, no matter the Ok or Cancel button has been pressed.
-		window.dialogArguments.Editor.FCK.Events.FireEvent( 'OnSelectionChange' ) ;
+		args.Editor.FCK.Events.FireEvent( 'OnSelectionChange' ) ;
 	}
 	window.close() ;
@@ -244,5 +274,5 @@
 function DisableContextMenu( targetDocument )
 {
-	if ( window.dialogArguments.Editor.FCKBrowserInfo.IsIE ) return ;
+	if ( args.Editor.FCKBrowserInfo.IsIE ) return ;
 
 	// Disable Right-Click
@@ -257,5 +287,5 @@
 DisableContextMenu( document ) ;
 
-if ( window.dialogArguments.Editor.FCKBrowserInfo.IsGecko && !window.dialogArguments.Editor.FCKBrowserInfo.IsOpera )
+if ( args.Editor.FCKBrowserInfo.IsGecko && !args.Editor.FCKBrowserInfo.IsOpera )
 {
 	window.onresize = function( e )
@@ -280,5 +310,5 @@
 }
 
-if ( window.dialogArguments.Editor.FCKBrowserInfo.IsIE )
+if ( args.Editor.FCKBrowserInfo.IsIE )
 {
 	function Window_OnBeforeUnload()
@@ -287,5 +317,5 @@
 			oTabs[t] = null ;
 
-		window.dialogArguments.Editor = null ;
+		args.Editor = null ;
 	}
 	window.attachEvent( "onbeforeunload", Window_OnBeforeUnload ) ;
@@ -294,5 +324,5 @@
 function Window_OnClose()
 {
-	window.dialogArguments.Editor.FCKFocusManager.Unlock() ;
+	args.Editor.FCKFocusManager.Unlock() ;
 }
 
@@ -323,6 +353,5 @@
 			<tr>
 				<td id="FrameCell" height="100%" valign="top">
-					<iframe id="frmMain" src="javascript:void(0)" name="frmMain" frameborder="0" height="100%" width="100%" scrolling="auto">
-					</iframe>
+					&nbsp;
 				</td>
 			</tr>
Index: /FCKeditor/trunk/editor/fckeditor.html
===================================================================
--- /FCKeditor/trunk/editor/fckeditor.html	(revision 1191)
+++ /FCKeditor/trunk/editor/fckeditor.html	(revision 1192)
@@ -31,4 +31,44 @@
 	@Packager.RemoveLine -->
 	<script type="text/javascript">
+
+// Save a reference to the default domain.
+var FCK_ORIGINAL_DOMAIN ;
+
+// Automatically detect the correct document.domain (#123).
+(function()
+{
+	var d = FCK_ORIGINAL_DOMAIN = document.domain ;
+
+	while ( true )
+	{
+		// Test if we can access a parent property.
+		try
+		{
+			var test = window.parent.document.domain ;
+			break ;
+		}
+		catch( e ) {}
+		
+		// Remove a domain part: www.mytest.example.com => mytest.example.com => example.com ...
+		d = d.replace( /.*?(?:\.|$)/, '' ) ;
+
+		if ( d.length == 0 )
+			break ;		// It was not able to detect the domain.
+		
+		try
+		{
+			document.domain = d ;
+		}
+		catch (e)
+		{
+			break ;
+		}
+	}
+})() ; 
+
+// Save a reference to the detected runtime domain.
+var FCK_RUNTIME_DOMAIN = document.domain ;
+
+var FCK_IS_CUSTOM_DOMAIN = ( FCK_ORIGINAL_DOMAIN != FCK_RUNTIME_DOMAIN ) ;
 
 // Instead of loading scripts and CSSs using inline tags, all scripts are