thank u very much for ur support.
i done it.
Dim objUser As UserInfo = UserController.GetCurrentUserInfo
Dim user4mapping As String
user4mapping = objUser.Username
Page.ClientScript.RegisterClientScriptBlock(Me.GetType(), "popup", "window.open('
http://192.168.151.15:88/webform1.a...?username=" & user4mapping & "','','scrollbars=no,menubar=no,height=650,width=screen.width,resizable=no,toolbar=no,location=no,status=no')", True)