I'm trying to setup a simple data entry form using a couple of related databases.

eg. I have 3 tables: Customers, Locations, Orders
Customers table contains:
ID: Integer (primary key)
CustName: Text

Locations table:
ID: Integer (primary key)
Location: Text

Orders table:
ID: Integer
Date: Data/Time
Desc: Text
CustID: Integer - (Source customers, Bound column: id, Visible column: CustName)
LocID: Integer - (Source: locations, Bound column: id, Visible column: Location)

I have tried to setup my form to try to capture new data by using a ComboBox to display "Customer" and "Location" information.
The form is displayed as I expected it by giving me a drop-down box with the entries in the Customers and Locations tables respectively which I can select the appropriate entry.
However when I save a record from the form, this information (CustID/LocID) is not saved in the Orders table.
If I enter the data directly into the table (not using a form), I get drop-down boxes displaying the data and the ID is saved in the table.

My question is: How should I design my forms in order to capture data from other tables in my table ?

Sorry, forgot to say I'm using Kexi v2.5.2 on KDE 4.9.5 in Ubuntu 12.04