Using Javascript, is there a way to do this?  Every time the .ascx page loads I want to use Javascript to popup a radAlert box.

This .ascx has no form or body.

Thanks

Unless I've missed something, .ascx files must exist within an .aspx page at some point in order to be displayed in a browser.  So, the .aspx page will have to have a form in order to use the RadControls for ASP.NET AJAX, and that's where you should put a RadWindowManager.  So, on your .aspx page:

<telerik:radwindowmanager runat="server" id="RadWindowManager1" />

And in your .ascx page add the following script:

Sys.Application.add_load(alertTheUser);

function alertTheUser() { radalert('Hello World'); }

Which will use the RadWindowManager from the .aspx page.  Hope that helps,

Shaun.