OnSelectionChange event in certain Controls don't fire when using Firefox.

[zonecheung]

This happened to 'dropdown list', 'radio button', and 'check box'. I think the right-click context menu is also using this event.

Step to reproduce:

1. Using Firefox, go to the Demo and use Sample 01.

2. Create either a radio button, check box, or drop-down.

3. Try to right-click on any of those. None of them showing the context menu, in my app., the OnSelectionChange event is not fired.

[w.olchawa]

DUP of #703