js判断间隔时间

js判断间隔时间

function timer()
{
var l = (new Date()-Date.parse(document.lastModified))/1000/3600/24);
alert(l);
if(l>1)
{
new Ajax().getData("MakeIndex.aspx","isAjax=true",function(obj){var a="";});
}
}
timer();