Description:
------------
Varible Property Retrivel

Test script:
---------------
class y{
   public $u = 123;
}
class a{
   public $b = null;
   public function __construct($test){
      $this->b = $test;
   }
   public function $c(){
      $p = new y();
      $p->u;           //Works
      $p->$this->b;    //Causes Error???
      $tmp = $this->b;
      $p->$tmp;        //Works
   }
}
$xyz = new a('u');
$xyz->c();