What's wrong with this?

[skyraker]

function ABT.initBookTrack(code, addOnName)
    if (addOnName == "BookTracker") then
        SLASH_COMMANDS["/mybooks"] = ABT.showBookWindow
    end
end
 
EVENT_MANAGER:RegisterForEvent("bookTrack", EVENT_ADD_ON_LOADED , ABT.initBookTrack)

The slash command is not being added. Yes, ABT.initBookTrack is defined. Yes, BookTracker is the title of the addon in my txt file.