Simple PHP User Management Script

Attached is a structure of a database consisting of three tables: tradesystems, tradeusers, and usersystemx. This project is to design a simple PHP application that will allow the editing, insertion and deletion of records in the tradeusers table. There must be initial authentication on the site using the systemid / systempasswd in the tradesystems table and the only users that can be editted are ones in which the systemid used to login is in the usersystemx table (so that only those acct_ids are accessible). In addition, on an insert, a record needs to be inserted into usersystemx table with the appropriate acnt_id and systemid (used to logon).