Adding referrer code

Hi all, I’m new here, but familiar with WP, no expert. I’m trying to install code that will record the source site of web visitors who make an enquiry. ie at the bottom of their emailed enquiry something like this:

referrer: http://www.facebook.com

I have Contact Form 7 installed, but using options tied to Analytics isn’t practical for me.
Here’s one I found but it doesn’t seem to work, only gives my own site url. http://www.fldtrace.com/wordpress/referral-conversion-tracking-with-wordpress-contact-form-7

Any pointers to something similar or what’s wrong with this code, or my setup. I’m not much of a coder I’m afraid.

Thanks