if (document.images)
    {
      preload_image_object = new Image();
      // set image url
      image_url = new Array();
      image_url[0] = "<?php echo $this->escape($this->imgDir); ?>/menu/about-us2.gif";
      image_url[1] = "<?php echo $this->escape($this->imgDir); ?>/menu/contact2.gif";
      image_url[2] = "<?php echo $this->escape($this->imgDir); ?>/menu/faq2.gif";
      image_url[3] = "<?php echo $this->escape($this->imgDir); ?>/menu/home2.gif";
      image_url[4] = "<?php echo $this->escape($this->imgDir); ?>/menu/request-a-quote2.gif";
      image_url[5] = "<?php echo $this->escape($this->imgDir); ?>/menu/why-buy2.gif";
      
      
      
       var i = 0;
       for(i=0; i<=5; i++) 
         preload_image_object.src = image_url[i];
    }