title: Notice: Undefined index: HTTP_X_FORWARDED_FOR Error in Function
body: <p>I'm getting Notice: Undefined index: HTTP_X_FORWARDED_FOR in the Function below:</p>
  
  <pre><code>function _ip( )
  {
      return ( preg_match( "/^([d]{1,3}).([d]{1,3}).([d]{1,3}).([d]{1,3})$/", $_SERVER['HTTP_X_FORWARDED_FOR'] ) ? $_SERVER['HTTP_X_FORWARDED_FOR'] : $_SERVER['REMOTE_ADDR'] );
  }
  </code></pre>