1 Combobox with values from 2 tables

[Comsoft]

Hello all. I'm very new to using access.
I Have to tables, Employee's & Vehicle's. I'm making a dispatch form. and i want to put a "Unit Dispatched" combo box that will populate from the Employee's ID and the Vehicle ID. We sometimes dispatch employee's to a job on their own and sometimes we send a company vehicle. is there any way to do this?

[June7]

Are these two tables related? What data are you saving - EmployeeID and VehicleID? Then I expect need two comboboxes.