How do I check what page a person was referred by?

[PhaZZed]

I saw a website... it displayed a list of all the websites, which ppl has been reffered from, how is this done?

I am thinking that there must be a built in php function?

[mrJazz]

You can check the referrer by calling an Apache Enviroment variable:

<?

print getenv('HTTP_REFERER');

?>

[bastien]

$referer = $_SERVER('HTTP_REFERER');

hth

[Pigmaster]

This works very well if there was a refering page, but if there was no refering page (i.e. a direct link) then I get
Notice: Undefined index: HTTP_REFERER

How can one overcome this. to avoid this Undefined prefix.

I have tried isset but this does not work.