Create AJAX Staff Scheduling Software; php, mysql to specification

We are looking to have PHP software developed using MySQL database - most of tables already exist in which we will need to integrate so the scheduler will integrate with our current software for business operations We would like for scheduling to be a drag and drop process using AJAX or similar to remove need for page reloads and to make software more elegant. Requirements: •Integrates with current database •Drag and drop scheduling •"Repeat last weeks schedule" and "saved default schedule" options •Different user levels showing different displays: •Admin: Create users, employees, and modify settings •Scheduler: Create schedule and complete functions related to scheduling •Employee: ability to view released schedule, request days off, request shift trades, request specific open overtime dates •Software should have setable settings to control alerts of weekly overtime per employee, how close together shifts can be to eachother without alerting, etc. •More details as discussed