Simple warehouse items management

This is a very simple program for maintaining database items in stock. At its core contains a table that has four data - name, unit of measure, quantity and price. In addition to this also includes an auxiliary table that contains the unit of measure, and is associated with the main table. Auxiliary tables should have options: add, edit and delete (unit of measure). The main table should have options: add, edit and delete (item storage). Besides all this, there should be options for entry and exit of goods. Upon receipt of the goods has to appear in a form with all the articles, which allows you to enter the amount of each article entering in a warehouse. After clicking on the 'submit' button, these quantities are to be added to the current amounts. At the same, output of goods will be released form with all the articles which allows you to enter amounts that come out of storage (ie sold). After clicking on the 'submit' button, these quantities should be subtracted from the current amounts. For now we will not implement any options related to suppliers, customers, creating purchase orders and invoices, but it is possible that the program expand in the future some of these options. The technology required for the design of this program is a PHP / MySQL.