This is a general knowledge question which is not directly related to the scope of service of Telerik forums. That is why my recommendation is to search in Google or in the ASP.NET forums for examples on how to remove dynamically generated server elements, e.g. https://www.google.com/search?q=Controls.Remove
the Telerik team
If you want to get updates on new releases, tips and tricks and sneak peeks at our product labs directly from the developers working on the RadControls for ASP.NET AJAX, subscribe to their blog feed now.