Shipment Tracking System PHP/MySQL

I want to build an automated shipment tracking system to help my customers locate their packages easier and fast. Requirements: - Standalone script on subdomain - Ability to login as customer, account creation agent, and admin all separately - Account creation agent should be able to generate a username for the customer and have an 8 character password auto generated for the customer and emailed automatically when the customers email is entered in and account is saved. I want us to create the accounts and auto email the clients so they can login and check their shipment status. I want one of my shippers to be able to loin each day and put the tracking numbers for all the packages mailed for the day so the customer knows if the packages have shipped or now. I need just basic fields for the customer. Name, address, phone number, email. I would like an option for multiple packages to be tracked in the system because some customers get 4-5 packages at a time. The system needs to be secure and clean looking. I would like to use the main site logo but otherwise keep it clean. If we can integrate the API from USPS into it so they don't have to leave the site to track that would be even better. So basically: User Creation Agent>Loads customer info Customer Logs in and check status of order Shipper adds tracking number to system for user update>auto email should go to customer once tracking is entered Can you do a basic script for this? I picked PHP/MySQL but if you have a better way to make this better for the user please make your point in the PM.