function Clock() {
 var date = new Date();
 this.year = date.getFullYear();
 this.month = date.getMonth() + 1;
 this.date = date.getDate();
 this.day = new Array("星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六")[date.getDay()];
 this.hour = date.getHours() < 10 ? "0" + date.getHours() : date.getHours();
 this.minute = date.getMinutes() < 10 ? "0" + date.getMinutes() : date.getMinutes();
 this.second = date.getSeconds() < 10 ? "0" + date.getSeconds() : date.getSeconds();

 this.toString = function() {
  return "现在是:" + this.year + "年" + this.month + "月" + this.date + "日 " + this.hour + ":" + this.minute + ":" + this.second + " " + this.day;
 };//现在是<SPAN id=clock>现在是:2013年3月6日 13:54:17 星期三</SPAN>

<SPAN></SPAN>
 this.toSimpleDate = function() {
  return this.year + "-" + this.month + "-" + this.date;
 };//2013-03-06

 this.toDetailDate = function() {
  return this.year + "-" + this.month + "-" + this.date + " " + this.hour + ":" + this.minute + ":" + this.second;
 };//2013-03-06 13:45:43

 this.display = function(ele) {
  var clock = new Clock();
  ele.innerHTML = clock.toString();//显示方式调用
  window.setTimeout(function() {clock.display(ele);}, 1000);
 };
}