Telerik Supports RadAlert, RadConfirm and RadPrompt
to show the message box. You can replace the standard alert, confirm, and prompt dialog boxes that are provided by the browser when you call the window.alert, window.prompt and window.confirm commands. The replacement dialog boxes are called with the radalert, radprompt and radconfirm methods, correspondingly. The replacement popups are implemented using RadWindow, and are a good deal more flexible than their browser counterparts. You can call these from both server side and client side. Please have a look into this help documentation
and online demo
for further information.