adding variable to page

ok, i'm using asp.net 2.0 and i need some help advice
i want to tag a querystring onto all my links
in asp i could just write <%=navControl%> and use my asp include file to run my function every page and spit out the querystring addition


I placed the following function into my master page code behind and called it on page load
Public Shared Function navControl() As String
        Dim qString As String = ""
        If Not HttpContext.Current.Request.QueryString("userID") Is Nothing Then
            'no userid qstring exists yet
        Else
            Dim userID As String = HttpContext.Current.Request.QueryString("userID")
      &nbs ...