IE9 event listener cant access target

[fahimc]

popularItem.addEventListener(MouseEvent.CLICK,this.onButtonClick);

public.onButtonClick=function(evt)
{
trace(evt.currentTarget);
switch(evt.target)
{
case searchItem.element:
obj.dispatch(ButtonEvent_SEARCH_CLICKED.name);
break;
case playlistItem.element:
obj.dispatch(ButtonEvent_PLAYLIST_CLICKED.name);
break;
case popularItem.element:
obj.dispatch(ButtonEvent_POPULAR_CLICKED.name);
break;
}
}