Simple php modification to an existing code.

We have a simple php script that we use to sell our traffic, currently the script is set where we set the prices for the ad spot on the admin panel and the advertiser can choose the ads spot and pay the specified price. We would like to add an extra input in the advertiser create ad form where the advertiser can buy the package multiple times by inserting the number needed. and this input will affect the total views number inserted in the db and the total price as well. We will provide ftp logins to a working instance of the script as well as admin logins, we expect this job to be done immediately. Regards