var tip = document.getElementById("tips").getElementsByTagName("dl");
var big = document.getElementById("big_img").getElementsByTagName("li");
function change(id) {
	if (typeof(isround) != 'undefined')
		clearTimeout(isround);
	var bigimg = document.getElementById("big_img").getElementsByTagName("li");
	var tip = document.getElementById("tips").getElementsByTagName("dl");
	for (var i = 0; i < tip.length; i++) {
		bigimg[i].className = "undis";
		tip[i].className = "";
	}
	bigimg[id - 1].className = "dis";
	tip[id - 1].className = "current";
	if ((next = id + 1) > tip.length)
		next = 1;
	isround = setTimeout('change(' + next + ')', 5000);
}
change(1);