Dim sQS as String = Request.QueryString.ToString
For Each eItem In Split(sQS, "&")
Dim sName As String = Left(eItem, InStr(eItem & "=", "=") - 1)
Response.Write(sName _
& " = " & Request.QueryString(sName) _
& "<br>")
Next
и это короче, но основано на той же идее
For Each Key As String In Request.QueryString.Keys
Response.Write(Key & " = " & Request.QueryString(Key) & "<br>")
Next