Adding invoice Lines wit asp.net mvc

[jokerr]

I'm creating a asp.net applications with MVC 4 Technology, and i want to allow the end-user to enter line items onto an invoice. I want the user to have the ability to add as many line items as they wish to the invoice, and then when they are finished to be able to click the Save button on the form which would then write the invoice and all line item data to the database. Can somebody help guide me how to handle this?