title: Regex help need to match an ampersand OR and end of string
body: <p>I'm trying to create a regex to match part of a URL
  The possible URLs might be</p>
  <blockquote>
  <p>www.mysite.com?userid=123xy</p>
  <p>www.mysite.com?userid=123x&amp;username=joe</p>
  <p>www.mysite.com?tag=xyz&amp;userid=1ww45</p>
  <p>www.mysite.com?tag=xyz&amp;userid=1g3x5&amp;username=joe</p>
  </blockquote>
  <p>I'm trying to match the <code>userid=123456</code></p>
  <p>So far I have</p>
  <pre><code>Dim r As New Regex(&quot;[&amp;?]userID.*[?&amp;]&quot;)
  Debug.WriteLine(r.Match(strUrl))
  </code></pre>
  <p>But this is only matching lines 2 and 4.
  Can anyone help?</p>