It is good to know that everything is working fine now. I just want to add something as I see that I missed it in my previous reply - sorry about that.
Note that RadWindow can exist as a standalone control. This means that you can add it to the form, but you will not be able to use radopen() to open it - radopen(), radalert, radconfirm, radprompt, etc. functions belong to the RadWindowManager control.
If you create a RadWindowManager and RadWindow controls and add the RadWindow to the RadWindowManager's Windows collection, if you add the RadWindowManager to the form, you will be able to open the newly created RadWindow by using radopen().
If you create only RadWindow control and add it to the form, when you want to open it from the client, you should first get a reference to it and then call its show() method.
var oWnd = $find("<%= RadWindow1.ClientID %>");
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