Open form and subforms with selected values

[thames11]

Hi,

I have a combobox which is used to select a value and open a customer record form based upon the order item selected. If I select Orderitem ID 3 it corresponds to Customer ID 5 - so customer 5's details are shown on the form that opens.

However, within the customer form I have two subforms. The first shows the order details by order number, the second shows the order items by order. How am I able to select the customer, select the corresponding order and orderitem using a single Orderitem ID value from the combobox?

Many thanks