imgs=new Array(
						"images/1.gif",
						"images/2.gif",
						"images/3.gif",
						"images/4.gif",
						"images/5.gif",
						"images/6.gif",
						"images/7.gif");

		if (document.images) {
		  for (i=0;i<imgs.length;i++) {
		     img = new Image();
		     img.src=imgs[i];
		  }
		}

		function changeImage(i) {
			document.mainImage.src = imgs[i-1];
		}