jquery 获取服务器时间

/**
	2012-10-12 buy.js
	通过ajax方式返回服务器时间
*/
$(document).ready(function (){
	var url="/ajax/comm.shtml?action=getTime";
	jQuery.ajax(url,{
		data: "",
		dataType: "json",
		cache: false,
		success: function(req){
			callbackTime(req);
	    },
	    error: function(msg){
	    	alert("ERROR:请刷新页面!");
		}
	});
	$("#but1").click(function(){jqueryTest();});
});

var srv_nowtime;
function callbackTime(req){
	var timeArr = req.split("&");
	srv_nowtime = new Date(timeArr[0]).getTime();

	showTime();
	
	window.setInterval(showTime, 1000); 
}

function showTime(){
	srv_nowtime += 1000;
	var nowtime = new Date(srv_nowtime);
	var ymd = nowtime.getFullYear() + ""+ (nowtime.getMonth()+1) +""+ (nowtime.getDate()<10?"0"+nowtime.getDate():nowtime.getDate());	
	//alert(ymd);
	
}