That works spectacularly fine. The link sits in the page the form is invisible, click the link and it passes the hidden input's value to the asp page. All lovely, but with two problems:
1) Everytime a user clicks the link they get the 'Do you want to submit this form unencrypted across the internet" warning pop-up (unless they've disabled it). - which doesn't exactly inspire confidence.
2) Not very elegant is it?
So, anyway to get the same result but bypass the form? Any help much appreciated.