hi, how do i stop adding users to multiple groups. i would like to have the users in only one group. if the user is already in some group then should stop adding the same user to some other group should be stopped. how do i achieve thisjayaraja

Yes, You do this with Sharepoint Programming, Create List that has One Column (Users) When add user, add user to this list with Sharepoint Object Model, then whenever add user, check does these user has been added, if yes, remove users from textarea. for select from list, use CAML Query