JavaScript显示实时变化的系统时间

JavaScript显示实时变化的系统时间

<span id=localtime></span>
<script type="text/javascript">
function showLocale(objD)
{
        var str,colorhead,colorfoot;
        var yy = objD.getYear();
        if(yy<1900) yy = yy+1900;
        var MM = objD.getMonth()+1;
        if(MM<10) MM = '0' + MM;
        var dd = objD.getDate();
        if(dd<10) dd = '0' + dd;
        var hh = objD.getHours();
        if(hh<10) hh = '0' + hh;
        var mm = objD.getMinutes();
        if(mm<10) mm = '0' + mm;
        var ss = objD.getSeconds();
        if(ss<10) ss = '0' + ss;
        var ww = objD.getDay();
        if  ( ww==0 )  colorhead="<font color=\"#FF0000\">";
        if  ( ww > 0 && ww < 6 )  colorhead="<font color=\"#373737\">";
        if  ( ww==6 )  colorhead="<font color=\"#008000\">";
        if  (ww==0)  ww="星期日";
        if  (ww==1)  ww="星期一";
        if  (ww==2)  ww="星期二";
        if  (ww==3)  ww="星期三";
        if  (ww==4)  ww="星期四";
        if  (ww==5)  ww="星期五";
        if  (ww==6)  ww="星期六";
        colorfoot="</font>"
        str = colorhead + yy + "-" + MM + "-" + dd + " " + hh + ":" + mm + ":" + ss + "  " + ww + colorfoot;
        return(str);
}
function tick()
{
        var today;
        today = new Date();
        document.getElementById("localtime").innerHTML = showLocale(today);
        window.setTimeout("tick()", 1000);
}
tick();
</script>