pramodsin

Hi, Please let me know how can I make a product with custom fields. I want to add a quantity/points against each product which will be auto deducted base on usage by the clients. Also I want to add some topup product product which will have no validity just add the point/quantity against main product. I am a bulk emailing service provider this is my website smtpprovider.com and I am looking for a billing management system for my website. Regards Pramod