This is the OS X Server 10.6 forum, and the server software isn't usually found on MacBook Pro systems — I'll guess that you're really not running the server software here. (I mention this because resetting the administrative passwords with OS X Server software installed can be quite different...)
If you have a second administrative login, you can use that.
If you don't.... If you're running 10.6, boot the installer DVD and use the Utilities menu to reset your password.