// JavaScript Document
function Clock(){
 var objTime = new Date();
 var nowYear = objTime.getFullYear();
 var nowMonth = objTime.getMonth()+1;
 var nowDay = objTime.getDate();
 var nowHours = objTime.getHours();
 var nowMinutes = objTime.getMinutes();
 var nowSeconds = objTime.getSeconds();
 if (nowMonth<10) nowMonth=’0′+nowMonth;
 if (nowDay<10) nowDay=’0′+nowDay;
 if (nowMinutes<10) nowMinutes=’0′+nowMinutes;
 if (nowSeconds<10) nowSeconds=’0′+nowSeconds;
 var noTimeVal = ‘&nbsp;’+nowYear+’-'+nowMonth+’-'+nowDay+’&nbsp;&nbsp;’+nowHours+’:'+nowMinutes+’:'+nowSeconds+’&nbsp;’;
 try{
  if (document.getElementById(‘Clock’) == undefined){
   document.write(‘<div id="Clock">’);
   document.write(‘</div>’);
   document.getElementById(‘Clock’).innerHTML = noTimeVal;
  } else {
   document.getElementById(‘Clock’).innerHTML = noTimeVal;
  }
 } catch(e){alert(noTimeVal);}
 setTimeout(‘Clock()’, 1000);
}

然后在页面中想要显示的地方调用 :
<script language="javascript">Clock("Clock");</script>