Scusate, ma perchè uno script vbsctipt lato client non funziona con mozzilla?

eccolo:
codice:
<script language ="vbscript">
StartDate = Now()
EndDate = CDate ("21/03/2004")
DaysLeft = DateDiff("d", StartDate, EndDate )
n = daysleft
nn=4-len(n)
for i=1 to nn+1
n="n" & n
next 
for i=1 to len(n)
n1=mid (n,i,1)
document.write "[img].\images2\h" & n1 & ".gif[/img]"
next
</script>