title: RegEx to delete all double(or more) letter -> preg_replace
body: <p>Helo,</p>
  
  <p>I've this RegEx to delete double letter on a string :</p>
  
  <pre><code>&lt;?
  $string = "Heeeeelloo";
  echo preg_replace( '`(.*)\1`', '$1',$string)."\n";
  </code></pre>
  
  <p>The current result is : Heeelo</p>
  
  <p>But i would like this result : Helo</p>
  
  <p>What's wrong ?
  Thanks</p>