expire with SSI?

[Jane Withnolastname]

I have a site that lists my auctions on the main page. I use a
JavaScript to call an iframe to display the auction item until the
auction is over. Then it displays the eBay button (or nothing, if I
have further auctions still active). Here's what that script looks
like:
var ebimagetag='<iframe name="ebay-table" frameborder=0 width=430
height=353 marginwidth=0 marginheight=0 align=center
src="ebauction.htm"><\/iframe>'
var ebbutton='<iframe name="ebay-button" frameborder="0" width=92
height=35 marginwidth=0 marginheight=0 align=center
src="button.htm"><\/iframe>'
var today=new Date()
function ebexpireat(expiredate){
var expire=new Date(expiredate)
if (today.getTime()<=expire.getTime())
document.write(ebimagetag)
else
document.write(ebbutton)
}
followed by
<script type="text/javascript">
ebexpireat("September 16, 2003 21:00 EDT")
</script>
in the body.
What I'd like to do is get rid of the iframes and use SSI:

<!-- #include file='ebauction.htm' -->

But when I try to put that in the main script, of course, it reads it
as a comment. I feel like there must be a way to do this but my brain
can't quite get there.

Any ideas?

*Please no comments on my messy and/or extraneous scripting or my use
of tables. It's all on the agenda - I just wanna get this worked out
first!
Thanks!!!