[imp] Custom Login problem

[G G Papazoglou]

Hi. Could someone please explain how to config the custom_login.php file? I
have set the following as illustrated:

define('IMP_BASE', '/usr/local/apache/htdocs/horde/imp');
$server_key = 'imap';

but it doesn't work. When I hit the login button it transfers me to the
usual IMP login screen (login.php)

Thanks,
Greg