if (document.images)
    {
      preload_img = new Image();
      // set image url
      image_url = new Array();
		  image_url[0] = "images/1.jpg";
		  image_url[1] = "images/2.jpg";
		  image_url[2] = "images/3.jpg";
		  image_url[3] = "images/4.jpg";
		  image_url[4] = "images/5.jpg";
		  image_url[5] = "images/6.jpg";


      var i = 0;
      for(i=0; i<=4; i++) 
         preload_img.src = image_url[i];
    }

	function showPic (whichpic, placeholder) {
		if (document.getElementById) {
			document.getElementById(placeholder).src = image_url[whichpic];
			return false;
		} else {
			return true;
		}
	}