Cognos Connection Logon Problem

[rajanikumarv]

I am trying to do login to cognos connection using authentication. ive added a namespace "sample" under my directory server in access manager. added users, app server and data source. I have made the option Allow Anonymous Access to false in configuration  manager and uncheck Allow Anonymous Users in IIS authentication methods, and in authenticated access block,when i check integrated windows authentication, i get an error with page cannot be found. and when basic authentication is checked, i get a windows pop up asking for my user id and password. i am able to see my login screen now but after entering credentials, still i cannot login.

i am using LDAP namespace for authentication. i get an message "The provided credentials are invalid. Please type your credentials for authentication. " please some one suggest me how to proceed.