Only posibility for this I can see: An <img src="/cgi-bin/cookiecheck.pl"> script in that page. Personally I don't think that this is really functional for clients might turn image-loading off, and/or they don't send the cookie back because they just have received it and the user still might have a "Do you want to store this cookie?" window above it's client while the client finishes loading the page in the background. Or is this broken behavior and I'm just thinking queer?
Anyway, my point still is: It can't be done on a single request, there must at least be two of them. One to send the cookie and the next one that can check if the cookie is set.
use signature; signature(" So long\nAlfie");