Local command authorization lets you assign commands to one of 16 privilege levels (0 to 15). By default, each command is assigned either to privilege level 0 or 15. You can define each user to be at a specific privilege level, and each user can enter any command at their privilege level or below. The security appliance supports user privilege levels defined in the local database, a RADIUS server, or an LDAP server (if you map LDAP attributes to RADIUS attributes.
refer the following url for more info on privilege lebvels configuration:
http://www.cisco.com/en/US/docs/security/asa/asa80/configuration/guide/mgaccess.html#wp1042038