jQuery Grid Plugin - jqGrid

I am very new to jqgrid & also jQuery, so hope to get some help from here. When we click the edit button at the navigator, the default edit dialog will show the fields which we set editable=true, but what if i want to add another table field?

Example: My grid will load the Table Customer (customer Id & Name) but what i want is when i click edit, the edit dialog can show all Booking id related to this customer.

I tried to load the grid with joined SQL (SELECT * FROM Customer A, CustomerBooking B where A.CustomerId = B.CustomerId) with set BookingId (hidden: true), The grid load successfully, but when i click the row, it dont allow me to click on the row due to there are more than 1 row of CustomerId (the relationship is 1 to many, one customerId can have > 1 BookingId).

Is there any way when i click on the row then upon the edit dialog load, only i submit another query to get all the BookingId? Or any example to change edit dialog? Cause i may need to show other information from another table related to this customer.

I have stucked here for a few days , anyone can advise?

Thanks in advance!

Many Many Thanks!