// JavaScript Document
function tab(){
	var labels=document.getElementById("tab_product").getElementsByTagName("li");
	var part_1=document.getElementById("part_1");
	var part_2=document.getElementById("part_2");
	labels[0].onclick=function(){
		this.className="sel";
		labels[1].className="";
		part_1.className="show";
		part_2.className="hide";
	}
	labels[1].onclick=function(){
		this.className="sel";
		labels[0].className="";
		part_1.className="hide";
		part_2.className="show";
		}
}