Error during admin login

[Guest groaningeek]

Hello, when I try to log in to my admin area, i get the following error message:

Fatal error: Call to undefined function: treatget() in /home/safety/public_html/shop/admin/login.php on line 74

When i go to the admin login page, this is the url in the browser:

http://www.safetyfirstweb.com/shop/admin/login.php?goto=/shop/admin/index.php?

If i change it to be:

http://www.safetyfirstweb.com/shop/admin/index.php?

I can then get in to the admin area fine.

I have never had this problem before.

This is the function call in the login.php file:

if(isset($_GET['goto']) && !empty($_GET['goto'])){

header("Location: ".urldecode(treatGet($_GET['goto'])));

} else {

header("Location: ".$GLOBALS['rootRel']."admin/index.php");

}

Any help would be much appreciated!