Role Based Access Control and Role Based Security

Hi list, thank to the wonderful people on this list. I am planning a system that require access to the system based on Role, i love the implementation in SMF(www.simplemachines.org) that every modules can define there own role and but i don`t know how. Users will be in group like Administrator, Editor, Manager etc (i have seen such on Joomla) and each module can define the action each group can perform e.g An advertisement module will define something like 'Can add', 'Can edit own', 'can edit any', etc.. i am wondering what the database structure/PHP Class will look like. I found a database Schema on Access Control at http://www.databaseanswers.org/data_models/access_control/index.htm but i can`t figure out the implementation in PHP. Any idea will help. -- Share with free mind! Join the world largest open forum for hackers and programmers. http://www.tuwana.com