[02/03] Page doesn't Refresh on AJAX callback

Hi all I am using mouseover event to show tooltip on hyperlink.

for tooltip i used div and it need to retrieve infromation from Server side.
So i used AJAX to call server page..

The problem is i can send request to server but my page doesn't seems to refresh. probebly beco'z client don't know anything happened after server side response..

My server side code of Page Load is as follow

VB Code:

If Not Request("id") Is Nothing Then
                Response.Write("parth") ' This Code is fired when i cal it from AJAX - Client Side Script
            Else
                Call Connect()
            End If

I call Page load event using this AJAX code

VB Code:

xmlHttp.open("POST","MouseOverTooltip.aspx?id="+idValue,true);
    xmlHttp.send(null);  }

If anybody know the solution then plz tell me.