function preload(){
	heavyImage = new Image(); 
	heavyImage.src = "/images/1c.gif";
	heavyImage.src = "/images/2c.gif";
	heavyImage.src = "/images/3c.gif";
	heavyImage.src = "/images/4c.gif";
}

function updatePhoto(sourceImg,newImg){
	document.getElementById(sourceImg).src=newImg;
}