title: Annoying PHP error: "Strict Standards: Only variables should be passed by reference in"
body: <p>I have this small script made and I cant get this error:</p>
  
  <p><code>Strict Standards: Only variables should be passed by reference in C:\xampp\htdocs\includes\class.IncludeFile.php on line 34" off!</code></p>
  
  <p>Here is the page:</p>
  
  <pre><code>namespace CustoMS;
  
  if (!defined('BASE'))
  {
      exit;
  }
  
  class IncludeFile
  {
      private $file;
      private $rule;
  
      function __Construct($file)
      {
          $this-&gt;file = $file;
  
          $ext = $this-&gt;Extention();
          switch ($ext)
          {
              case 'js':
                  $this-&gt;rule = '&lt;script type="text/javascript" src="'.$this-&gt;file.'"&gt;&lt;/script&gt;';
                  break;
  
              case 'css':
                  $this-&gt;rule = '&lt;link type="text/css" rel="stylesheet" href="'.$this-&gt;file.'"&gt;';
                  break;
          }
      }
  
      private function Extention()
      {
          return end(explode('.', $this-&gt;file));
      }
  
      function __Tostring()
      {
          return $this-&gt;rule;
      }
  }
  </code></pre>
  
  <p>Please help me.</p>