Differences in support for focusin/focusout events by browsers

Browser version:

IE6/24/60/9

Ie10 preview2

Firefox 5

Safari 5

Chrome 12

Opera 11

Test:

	IE6/7/8	Ie9/10	Firefox5	Safari5	Chrome12	Opera11
El. onfocusin	Y	Y	N	N	N	Y
El. attachevent ('onfocusin ', FN)	Y	Y	N	N	N	Y
El. addeventlistener ('focusin ', FN, false );	N	Y	N	Y	Y	Y

Conclusion:
1. All ie versions support focusin/focusout events (Note: The El. addeventlistener method is not supported in IE6/7/8 ).
2. Opera supports attachevent and addeventlistener. Both methods support focusin and focusout events.
3. Safari/Chrome is a surprise. Although El. onfocusin is not supported
Addeventlistener Method . Therefore, to enable Safari/chrome to support focusin events, you can only add events using addeventlistener.
4. focusin/focusout is not supported for any method of adding events in Firefox.

Differences from focus/Blur :
focusin/focusout supports event bubbling, so you can implement event proxy for it.

related:
http://msdn.microsoft.com/en-us/library/ms536935%28VS.85%29.aspx
http://msdn.microsoft.com/en-us/library/ms536936%28VS.85%29.aspx