var image="../images/pages/gemstone_studs/half_ctw.jpg";
	function chncolor(obj,classname,src){
		obj.className=classname;
		if(src!=""){
			document.getElementById('mainimage').src=src;
		}else{
			document.getElementById('mainimage').src=image;
		}
	}
	function Tdcolor(obj,newclass){
		obj.className=newclass;
	}