>I am testing a code of using an UpdatePanel control with the code behind that validates an entry in a text box. The idea is to make the page do whatever it is supposed to do without re-posting. First I thought that it definitely works and the page is not re-posting. But then I noticed that the IE symbol on the tab of the page "jumps" or "flicks" just a tiny bit. But I am not sure. How do I verify/validate that the page is or is not reposing?

If you are trying to detect a postback, this might do it:

oProcess.oPage.IsPostBack

...where oPage is the object reference to your page.

You can also detect a post such as:

' If this is a post
If oRequest.ServerVariables("REQUEST_METHOD") = "POST" Then
   lPost = True
   Else
   lPost = False
End If