Write a script which prompts the user for input, asking for values for description, quantity and price. Remember that the stock item's ID will be automatically filled in by the database, as it is an "auto increment" field.
Next, create an SQL query to add a record to the database. Output a message to the user indicating the success (or failure) of the operation. A sample script to get you started is available in exercises/acme/addstock.pl
Check that the price is a number (use regular expressions for these checks)
Check that it has two decimal places
Check that the number of items in stock is a number