i serch about 1 month to find a script that names biorhythms and i found a script! my problem is that the script works in internet explorer but not in firefox and i do not know why!

i will sent the code...can any one help me and say to me what i have to do?thanks a lot and sorry for my english...i am from greece

code:

```
<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
var montharray=new Array("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec");
function countup() {
yr = (yea.value) ;
m = (mon.value) ;
d = (day.value) ;
var today=new Date();
var todayy=today.getYear();
if ((navigator.appName == "Microsoft Internet Explorer") && (todayy < 2000))
todayy="19" + todayy;
if (navigator.appName == "Netscape")
todayy=1900 + todayy;
var todaym=today.getMonth();
var todayd=today.getDate();
var todaystring=montharray[todaym]+" "+todayd+", "+todayy;
var paststring=montharray[m-1]+" "+d+", "+yr;
var difference=(Math.round((Date.parse(todaystring)-Date.parse(paststring))/(24*60*60*1000))*1);
birthm.value=difference;
ph.value=Math.round(100*Math.sin((2*Math.PI/23)*difference));
int.value=Math.round(100*Math.sin((2*Math.PI/33)*difference));
em.value=Math.round(100*Math.sin((2*Math.PI/28)*difference));
av.value=Math.round((parseInt(ph.value) + parseInt(int.value) + parseInt(em.value))/3);
}
// End -->
</script>
```