Auto fill a field value in an enum list based on a selection in a previous field

[A_Pay77]

If I select a value from an enum list in one field, can it prefill another field with the value from the enum list set up for that field? If so, where do I do this and what is the formula I use?

Example:
Fitting Type - can select (2ft fluro batten, 4ft fluro batten, downlight, tropher)
Lamp Type - can select (LED, Fluro, Circular Fluro, halogen)

If I select ‘2ft Fluro batten’ in Fitting Type I want it to fill in the Lamp Type column with ‘Fluro’