Advanced ebay search - php script

Require php script for advanced eBay search. Form with 3 fields will connect to php script that fills in variables and then forwards to the right ebay URL. Form fields are: 1) keyword (with text 'search this website' that disappears when the user clicks in the box) 2) country (drop down select) 3) category (drop down select) The form fields will fill in the variables required in the ebay link. Copyright of script will belong to me once completed. See attached brief for more details.