Returning Customers -Booking Reservations

[icandywebdesign]

Hi there,
I want a solution for a customer to register on the site and then if they complete forms for making a reservation (this is for a limo service), they can access those forms when they login next time and edit only the details that they want to change -this is for repeat customers so they do not have to re-enter their information every time.

What would be the best way to do this?

Thanks!