Accessing Javascript Variable In ASP

I have an asp page that is needing to validate data against database but to do so I need to pull in a key value from another web page. I can get the key value in ASP using the following javascript code:

<script>
var main = opener.opener;
var currQuote = main.document.forms[0].quotenum.value;
</script>

My problem is trying to figure out how to use currQuote in the ASP code surrounding the script. There's got to be a way to do it - I'm just burnt out trying to figure it out.