var now = new Date();
var pass = new Date('2010/04/16');
alert((now-pass)/1000/60/60/24+"天");

------解决方案--------------------

JScript code

var now = new Date();
var pass = new Date('2010/04/16');
var num = parseInt((now-pass)/1000/60/60/24)
alert(num+"天");

------解决方案--------------------

JScript code

var now = new Date();
var pass = new Date('2010/04/16');
var num = parseInt((now-pass)/1000/60/60/24)
alert(num+"天");

------解决方案--------------------
JScript code
<script>
var d1=new Date("2010/04/16 16:04:07");
var d2=new Date();
alert(parseInt((d2-d1)/(60*60*24*1000)));
</script>