Geeklog Forums

I've built a websurvey site using Geeklog. I'm using a cgi-based survey script that gathers form data. My question is, how can I call up the user id (i.e. the id they login with) within my html form so that the cgi script will be able to know who completed the survey? I know that I could ask them to enter their id, but I don't want to leave that up to them.

I'm a lowly grad student trying to get a project working, and so any help would be greatly appreciated.