Thank you for your answer, you were right .. I didn't modify the conf.php properly
Code:
$conf['sessionhandler']['params']['username'] = 'horde';
$conf['sessionhandler']['params']['password'] = 'myhorde';
these fields .. anyways I just pasted these so others can solve the problem if they encounter it .. I have another question though
now I can't login to horde at all .. I've checked table horde_users and it does have entry and password with md5 in the mysql but still I cannot login, do you perhaps know what is the problem this time .. Thank you