Removes the given handler for the "buttonDropDown" event. If there are duplicate entries, ALL are removed.
[Visual Basic] Public Sub RemoveOnButtonDropDown( _ ByVal handler As ToolBarButtonClickEventHandler _ ) [C#] public void RemoveOnButtonDropDown( ToolBarButtonClickEventHandler handler ); [C++] public: void RemoveOnButtonDropDown( ToolBarButtonClickEventHandler* handler ); [JScript] public function RemoveOnButtonDropDown( handler : ToolBarButtonClickEventHandler );