Pre-fill automatically a form field with part of the URL

[belper]

Hello,
I am developing a site with Dreamweaver CS3 and have a little knowledge of HTML.
I need a solution for the following:
Visitors can come to my site through a referrer for ex: www.domain.com/?ref=cesar017
The referrer’s information (cesar017) should be prefilled automatically in a form field on another page than the index page. This means the visitor first can look around on the other pages of the site and then go to the page with the form. I don’t use a database at this moment, I only want a certain field automatically prefilled with the referrer’s info from the URL for ex : In this case the field should have the value=”cesar017”
I understood this can be solved with Javascript or PHP and cookies, but I nearly don’t know anything about this and Dreamweaver has not automated this function.
Can somebody help me with this script (how, where * head - body section *…)
In advance thanks for your help

[Airshow]

Belper,

It's probably best to get index page to set a session variable. By doing so the referer value will be available to other web pages during the same user session.

I'm not a Dreamweaver person but you could try Googling "Dreamweaver session variables" or similar.

Alternatively, you could set a cookie which provides longer term storage of data, but it is stored client-side, not server-side.

For this try Googling "Dreamweaver cookies" or similar.

Airshow

[belper]

Hello,

First of all my apologies for the delay in my replay (I have been unable to post these last months for personal reasons. Thanks for understanding).
This is the solution that is working and is the best one for my needs :

Add this anywhere before your HTML begins to start the cookie.
PHP Code:

<?php
if(isset($_GET['ref']))
  setcookie('referrer', $_GET['ref'], time()+3600);
?>

cookie will remain on client-side for 1 hour. If you want to store the cookie for a longer period on client-side
time()+60*60*24*30 is seconds*minits*hours*days
if time is O or not mentioned, than the cookie will be canceled at the end of the session

Then use the cookie on your page with the form field :

<input type="text" name="referrer" value="<?php
  echo htmlspecialchars($_COOKIE['referrer']); ?>" />

Thanks to all the people that helped me.