title: C# regular expression (replace)
body: <p>Assume I have the string:</p>
  
  <blockquote>
    <p>10,11,12,13,14,ABC,DEF,GHI,66</p>
  </blockquote>
  
  <p>I am looking to run a regex against it to only return 0-9 and the "," characters, essentially stripping anything else out.</p>
  
  <p>I have looked at Regex.Replace, but something isn't quite right with it. My code below:</p>
  
  <pre><code>Regex reg = new Regex(@"[0-9,]+");
  string input = reg.Replace(input, delegate(Match m)
                  {
                      return String.Empty;
                  });
  </code></pre>
  
  <p>How can I make this work?</p>