使用JavaScript显示当前系统时间

// 时间日期显示函数
function ShowTime(objID)
{
    var NewDate=new Date();
    var Year=NewDate.getYear();
    var Month=NewDate.getMonth()+1;
    var DayS=NewDate.getDate();
    var Hour=NewDate.getHours();
    var Minute=NewDate.getMinutes();
    var Second=NewDate.getSeconds();
    var Xday;
    var ShowStr;
               
    if(navigator.userAgent.indexOf("MSIE")==-1)
       Year=1900+Year;
                  
    switch(NewDate.getDay())
     {
       case 0:Xday="星期日";
           break;
       case 1:Xday="星期一";
           break;
       case 2:Xday="星期二";
           break;
       case 3:Xday="星期三";
           break;
       case 4:Xday="星期四";
           break;
       case 5:Xday="星期五";
           break;
       case 6:Xday="星期六";
           break;
    }
               
    if(Month<10)
        Month="0" + Month;
                 
    if(DayS<10)
        DayS="0" + DayS;
               
    if(Hour<10)
        Hour="0" + Hour;
               
    if(Minute<10)
        Minute="0" + Minute;
                 
    if(Second<10)
        Second="0" + Second;
                 
     ShowStr=Year + "年" + Month + "月" + DayS + "日";
     ShowStr +="  " + Xday + "  ";
     ShowStr +=Hour + ":" + Minute + ":" + Second;
               
     document.getElementById(objID).innerHTML =ShowStr;
}

前台代码：

<li class="menuright"><span id="showtime"></span>

     <script type="text/javascript">
               setInterval("ShowTime('showtime')",1000);
      </script>

</li>