Add discount box form to classic asp page

I need to urgently add a discount input box on a particular page of the website. The end user will enter a discount code into the box and a discount will be applied to the cost of a subscription. The discount code should be stored in the main site access database, as should the cost of the subscription after the discount is applied. Everything on the site is controlled via this database so I dont want it controlled any other way. This is urgent and needs completing in the next half an hour. FTP access will be given to the winning bidder, as will the site address.