PHP/Mysql Simple Invoice

I'm in need of a very simple php "invoice" system. I just need the portion of the invoice system that does the creation of the invoice. The database structure is: table invoice: id, date, paid (1 or 0), comments, incidentid, name, address1, address2, amount paid, staffid, leaseid, clientid table invoiceitems: id, invoiceid, itemid, quantity table items: id, name, description, unitcost,saleprice Must have: Ability to add/remove rows Ability to autofill Name, description and cost Ability to allow modification of cost Calculation of line total Calculation of subtotal The current site utilizes the AdminLTE template system (bootstrap)