[otrs] Integrating LDAP

Hi, Please let me know the steps to integrate LDAP with OTRS.I have tried few things mentioned below but not able to authenticate Active directory user I have followed steps mentioned at link http://doc.otrs.org/1.3/en/html/ldap-integration.html and restarted apache server.Net::LDAP module is already there in the system. Are there any other steps or care to be taken. Thanks and Regards, Manish