Using gridview to save and update data

Hi,

I have a gridview with empty data template in a page where i am saving company details and using gridview to save contact person details.. i am using gridview coz in case user wants to save more no of contact person details for the same company id it will be convenient. Also When user wants to update the company details along with related contact persons if any.... there should be again a provision to add one or more contact persons at the time of updating the company details..

How to do this please help