I assume this is a Perl question -- I'm ignorant about these things! This much I know -- my web site is run on a Unix system. Apache, as I recall, my system administrator told me.
I have put my banner on different web sites. When the user clicks on the banner s/he is sent to my web site. I would like some way to identify the source web site so that if the user becomes interested in my product, and decides to click on my email form, there appears on the subject line of the email form the name (or some brief numeric code) of the web site that referred that person to me.
So in other words, I need a way to grab the url/domain name where the person came from, and then whenever that person clicks on my page's email form, there appears on that email subject line a code that lets me know where that person came from -- so I later can credit the referring web site when I look at the email I received. (Whew!)
If that's all the CGI script did, I would be happy. But it would be even nicer, if at the same time it added the code to the email, it also put carbon copy infomation so that if the person emailed me a form, it also sent a carbon copy of their email to the email address of the web site that the person came from, so that the person who's site my banner ran on got notified that the person sent me email.
Obviously many times a person would arrive on my site from a domain/url where I have NO banner, so in that case the CGI script would put a code on the email that the person came from a URL/domain where I have no banner.
Of course I would have a list of the email addresses of those web sites where I have placed my banner, so that the CGI script could refer to that list when it does its thing.
I hope I (a certified CGI Ignoramus) have provided enough information so that one of you experts can provide a solution. And yes, I have access to my CGI-BIN.