function changImage(obj){
		var length = (obj.src.length-5);
		var src = obj.src.substr(0,length);
		src += "a.jpg";
		obj.src = src;
}
function changBack(obj){
		var length = (obj.src.length-5);
		var src = obj.src.substr(0,length);
		src += "p.jpg";
		obj.src = src;
}
function imageChanger(obj){
	var length = (obj.src.length-10);
	var src = obj.src.substr(0,length);
	src += ".jpg";
	document.getElementById("big").src = src;
}