# OnClientButtonClicking

The **OnClientButtonClicking** client-side event occurs when the user clicks on a ribbonbar button, before the ribbonbar responds to the mouse click.

The event handler receives two parameters:

1. The instance of the ribbonbar firing the event.

2. An eventArgs parameter containing the following methods:

   * **get_button()** returns a reference to the ribbonbar button that was clicked. In this case it is **RibbonBarButton**.

   * **set_cancel()** lets you prevent the ribbonbar from responding to the mouse click. You can use this event to respond when the user clicks on a ribbonbar button:

```JavaScript
<script type="text/javascript">
    function OnClientButtonClicking(sender, args) {
        args.set_cancel(true);
    }       
</script>
```

```ASPNET
<telerik:RadRibbonBar RenderMode="Lightweight" ID="RadRibbonBar1" runat="server" OnClientButtonClicking="OnClientButtonClicking">
    <telerik:RibbonBarTab Text="Home">
        <telerik:RibbonBarGroup Text="Clipboard" EnableLauncher="true">
            <Items>
                <telerik:RibbonBarButton Size="Medium" Text="Cut" ImageUrl="icons/Cut.png" />
                <telerik:RibbonBarButton Size="Medium" Text="Copy" ImageUrl="icons/Copy.png" />
            </Items>
        </telerik:RibbonBarGroup>
    </telerik:RibbonBarTab>
</telerik:RadRibbonBar>
```

* **set_enabled()** - disables a RadRibbonBarButton when set to **false**.

* **get_enabled()** - returns **true** if the RadRibbonBar is enabled and **flase** when it is disabled.

```JavaScript
<script type="text/javascript">
	function OnClientButtonClicking(sender, args) {
		var button = args.get_button();
		button.set_enabled(false);			
	}

</script>
```

```ASPNET
<telerik:RadRibbonBar RenderMode="Lightweight" ID="RadRibbonBar1" runat="server" OnClientButtonClicking="OnClientButtonClicking">
    <telerik:RibbonBarTab Text="Home">
        <telerik:RibbonBarGroup Text="Clipboard" EnableLauncher="true">
            <Items>
                <telerik:RibbonBarButton Size="Medium" Text="Cut" ImageUrl="icons/Cut.png" />
                <telerik:RibbonBarButton Size="Medium" Text="Copy" ImageUrl="icons/Copy.png" />
            </Items>
        </telerik:RibbonBarGroup>
    </telerik:RibbonBarTab>
</telerik:RadRibbonBar>
```

## See Also

* [Client-Side Programming Overview](https://www.telerik.com/products/aspnet-ajax/documentation/controls/ribbonbar/client-side-programming/overview)

* [Client-Side Events Overview](https://www.telerik.com/products/aspnet-ajax/documentation/controls/ribbonbar/client-side-programming/events/overview)