Link to capture customer_id from grid and to fill it in another application

Hi,

I have a grid (grid_appointment), based on table appointment(app_id, date, customer_id)

Also an appointment form, where i can choose which customer to appoint.

Now, when I call a customer (from the grid data), and the customer wants to postpone his appointment, I want to click … to get the appointment form with his customer_id already in the form (new record); just have to fill date, etc for a NEW appointment.

How do I go about this, has been spending 2 days looking for solution.

Thanks for replying.