title: Compilation failed: nothing to repeat at offset 6
body: <p>im not sure why this wont work... works perfectly in multiple <code>regex</code> checkers and testers. but when it comes to running it in <code>PHP</code> i get this error:</p>
  
  <pre><code>Warning: `preg_match()` [function.preg-match]: 
  Compilation failed: nothing to repeat at offset 6 in /home/splose/public_html/index/index.php on line 49
  </code></pre>
  
  <p>im running this:</p>
  
  <pre><code>if(preg_match('[\\/^$.|?*+():&lt;&gt;]', $username)){}
  </code></pre>