Custom Company Messenger

Not sure of the programming platform but I need a customized Messenger system (much like Yahoo or AIM) but company specific. There should be an admin page where I can create a database and login information for each employee/user. The program will show employees currently logged into system and able to communicate to each other via instant message. If employee is offline then the option to send an offline message should exist. Employees should be subdivided into organizational structure depending on which employee or manager they report to. Employees should only have access to instant message other members in their work group, and their reporting manager, All transcripts should be logged and sent at the end of each conversation to administrator via email and then archived. A profile should be accessible to each user which will include specified information from the database that the admin created. Very simple coding -- nothing extreme or complicated. Budget is not high on this so please do not overbid.