check referrer issue

Hi

There appears to be a problem with the check referrer setting in index.php on line 82

When set to default setting of
        // Check referer
      RereferCheck();

the following message is displayed when attempting to log in:

Fatal error: Call to undefined function RereferCheck() in /newsin/index.php on line 82
(I have removed the home directory info at the start of the link in the text above)

When already logged in and login is set to 'remember me' the problem does not exist.

Anyone trying to log in afresh however gets the error message.

Commenting out the line RereferCheck(); removes the problem.

Any suggestions why this is happening would be appreciated.

Rgds