 <p>Use one of these: </p> <pre><code>match += request + "\r\n"; </code></pre> <p>Use an string literal:</p> <pre><code>match += request + @" "; </code></pre> <p>OR only at runtime will this resolve:</p> <pre><code>match += request + System.Environment.NewLine; </code></pre> <p>On Unix <code>"\n"</code></p>