Javascript 日期比较

<script type="text/javascript">
//mydate yyyy-MM-dd 格式
function CompareWithTody(mydate)
{
var stoday = new Date();
var syear =Number(stoday.getYear().toString()); //在firefox下得再加1900
var smonth = (stoday.getMonth()+1).toString();
var sday = stoday.getDate().toString();
if(smonth.length == 1)
{
smonth = "0"+smonth;
}
if(sday.length == 1)
{
sday = "0"+sday;
}
var strToday = syear+"\/"+smonth+"\/"+sday;
var d1=new Date(Date.parse(mydate));//转化成日期格式以后,再进行比较
var d2=new Date(Date.parse(strToday));
return d1>d2

}
</script>