how to approve new xwiki users ?

Hi all, I would like to known if it is possible to have a way to approve new xwiki users registerations at my xwiki. If a features like this doesn't exist, please give some pointers on how to implement this. thank you. -- Claudio Miranda _______________________________________________________________ http://www.claudius.com.br/blog http://www.summa-tech.com http://www.soujava.org.br