The OnClientItemsRequestFailed client-side event occurs when an error has occurred while loading elements using the load-on-demand mechanism.

The event handler receives two parameters:

1. The instance of the combobox firing the event.

2. An eventArgs parameter containing the following methods:

   • get_errorMessage returns the error message.

   • set_cancel lets you prevent the default error message from displaying.

You can use this event to hide the default error message that appears in the combobox and display your own message instead:

CopyASPX

<script language="javascript" type="text/javascript">  
function OnClientItemsRequestFailedHandler(sender, eventArgs)  
{    
    alert("My custom error message");
    // set cancel to hide the default message        
    eventArgs.set_cancel(true);
}
</script>
<telerik:radcombobox 
    id="RadComboBox1" 
    runat="server" 
    enableloadondemand="True" 
    onitemsrequested="RadComboBox1_ItemsRequested"
    onclientitemsrequestfailed="OnClientItemsRequestFailedHandler">
</telerik:radcombobox>