On-line sale process using a computer and a system for the same

An on-line sale system using a computer, wherein a business web site is set up in a server of a enterprise such that the enterprise can go on line to purchase what they want from any one of clients, and wherein the web site mainly has a client trading system that allows a plurality of clients going on line to register their basic information and purchase the products they want to purchase, the client trading system comprising:

• an inquiry management system which is a management system for the client to show the enterprise an inquiry;
• an inquiry/negotiation management system which manages inquiry/negotiation between the enterprise and the clients;
• a product trading management system which is used to manage the products the client wants to purchase;
• and
• a purchase order searching management system which is used for the clients to manage the purchase order.