title: Regular expression negative match
body: <p>I can't seem to figure out how to compose a regular expression (used in Javascript) that does the following:</p>
  
  <p>Match all strings where the characters after the 4th character do not contain "GP".</p>
  
  <p>Some example strings:</p>
  
  <ul>
  <li>EDAR - match!</li>
  <li>EDARGP - no match</li>
  <li>EDARDTGPRI - no match</li>
  <li>ECMRNL - match</li>
  </ul>
  
  <p>I'd <em>love</em> some help here...</p>