JavaScrip获得当前日期的前一天

<mce:script language="javascript" type="text/javascript"><!--
function GetDay()
{
var   today=new   Date();
var   yesterday_milliseconds=today.getTime()-1000*60*60*24;
var   yesterday=new   Date();
yesterday.setTime(yesterday_milliseconds);

var strYear=yesterday.getFullYear();
var strDay=yesterday.getDate();
var strMonth=yesterday.getMonth()+1;
if(strMonth<10)
{
strMonth="0"+strMonth;
}
var strYesterday=strYear+"-"+strMonth+"-"+strDay;
alert(strYesterday);

//关闭页面，无提示

window.opener=null
window.open("","_self")
window.close();
}

// --></mce:script>