title: C# Regex Pattern Conundrum
body: <p>I have a regex that I've verified in 3 separate sources as successfully matching the desired text.</p>
  
  <ol>
  <li><a href="http://regexlib.com/RETester.aspx" rel="noreferrer">http://regexlib.com/RETester.aspx</a></li>
  <li><a href="http://derekslager.com/blog/posts/2007/09/a-better-dotnet-regular-expression-tester.ashx" rel="noreferrer">http://derekslager.com/blog/posts/2007/09/a-better-dotnet-regular-expression-tester.ashx</a>,</li>
  <li><a href="http://sourceforge.net/projects/regextester/" rel="noreferrer">http://sourceforge.net/projects/regextester/</a></li>
  </ol>
  
  <p>But, when I use the regex in my code.  It does not produce a match.  I have used other regex with this code and they have resulted in the desired matches.  I'm at a loss...</p>
  
  <pre><code>string SampleText = "starttexthere\r\nothertexthereendtexthere";
  string RegexPattern = "(?&lt;=starttexthere)(.*?)(?=endtexthere)";
  Regex FindRegex = new Regex(@RegexPattern);
  Match m = FindRegex.Match(SampleText);
  </code></pre>
  
  <p>I don't know if the problem is my regex, or my code.</p>