privilege levels for http server switch

i used the commad archive and extraced the tar file. using the ip http authentication enable, i can use web interface with secret password ( level 15 access) . i cannot do this with local username/password combo or tacacs+ authentication. one of the configuratuion i tried was-username ky privilege level 7 password cisco
enable secret level 7 cisco1
privilege exec level 7 configure terminal
privilege configure level 7 interface
i am unable to access with this username.
i also tried using tacacs+ configuration ( with checking shell (exec) and privilege 7)
can you throw some light or guide me to a good book on this subject
thanks for your time