hi every one. I need some ideas for the calculation. I have a form where admin can add the product. field names are Product_id,Name,Description,Quantity,Unit_price
now i have an other form which is used for buying products. What i want to do is when customer chooses the product, as soon as he/she enters the quantity it should automatically be multiplied by the unit price of that product e.g if unit price is 2pounds and quantity is 5 it should give me result straight away as 10. I am not sure which is suitable control for this .e.g Data gridview or some other controls. Really need help to get this done.