Simple way to catch referer using javascript and PHP?

[Emil]

Lets say I want people to put a small javascript on their site. This javascript should "send" the referer-URL to one of my PHP-scripts on my server.

How could this be done? All these webcounters use Javascript, can anyone plz explain how I can do this?

[redwhiteandblue]

You could do something simple like

<script language="Javascript" type="text/javascript">
<!--
var docRef = document.referrer
docRef = encodeURIComponent(docRef) //URI encode the referrer string
dummyPhpImg = new Image
dummyPhpImg.src = '/yourserversidescript.php?REF=' + docRef
//-->
</script>

Basically loads a dummy image object which is actually your php script, don't forget to send a header response as an img file at the of the script, it can be an empty 1x1 pixel image, doesn't matter as you're not going to display it. BTW you can add more parameters to the query string such as screen size, client time, etc.

[Emil]

Thank you!