Getting referrer, storing, retrieving to a form

For visitors from one particular site

[abbeyvet]

I am not very good at PHP and a bit lost about how to do this.

I want to track those who are referred from one particular site AND complete a form. I am not sure how to start, but it seems like this is the flow:

1. Get the referrer when they arrive at my site.
2. Make this into a parameter
3. Somehow store this parameter as they browse around
4. Retrieve the parameter when they come to fill in a form

1 and 2 I can do. If I have the parameter stored somehow I can do 4.

3. I am a not sure how to achieve. Any help appreciated.

[mipapage]

Hey abbeyvet,

You are going to need to use sessions [php.net] to track that user thru your site.

Also, I might suggest that rather then grab the referer, which can be unreliable (many people block passing a referer), maybe link with a type of affiliate id, so this site links to you like:

[yoursite.com?aid=foo...]

Where foo is what identifies the site that the user clicked thru from.