dear sir
 i want to know if the followign scenario has some work around possible
 i have a table to project_users and a table of users.
 when some one joins my organization i add him in the user table adn then when he becomes a part of a project he is added to the project users table
 to add him to a project he should not already be a part of that project
 so i want to execute a query of the form
  select user_id from users where user_id NOT IN ( select user_id from project_users where project_id = $selected_project)
 but as you know mysql doesn't support sub-select .]
 so is there a workatround using php to handle this sub select pls reply soon
 thanx
--akhil