public string OnClientDropDownOpened { get; set; }

Public Property OnClientDropDownOpened As String
	Get
	Set

public:
property String^ OnClientDropDownOpened {
	String^ get ();
	void set (String^ value);
}

member OnClientDropDownOpened : string with get, set

<script language="javascript">               

function HandleOpen(sender,args)
{
     alert("Opening combobox with " + comboBox.get_items().get_count() + " items");

}

</script>


<kettic:kaxcombobox 
      id="KaxComboBox1" 
      Runat="server" 
      OnClientDropDownOpened="HandleOpen">
</kettic:kaxcombobox>