public string OnClientSelectedIndexChanging { get; set; }

Public Property OnClientSelectedIndexChanging As String
	Get
	Set

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

member OnClientSelectedIndexChanging : string with get, set

<script type="text/javascript">               
    function onSelectedIndexChanging(sender, eventArgs)
    {
        var item = eventArgs.get_item();
        if (item.get_text() == "LA")
        {
            // do not allow selecting item with text "LA"   
            return false; 
        }
        else
        {
            // alert the new item text and value.
            alert(item.get_text() + ":" + item.get_value());
        }
    }                        
</script>

<kettic:kaxcombobox ID="KaxComboBox1" runat="server" 
      OnClientSelectedIndexChanging="onSelectedIndexChanging">
</kettic:kaxcombobox>