Not quite sure what you are asking, can you give a play by play example?
When a field is set up as a popup menu, clicking the field itself displays the popup menu, you don't need an additional button.
You want another field to be set to a return or space delimited list of all items on the value list?
Please expand on your question.
Also: What version & what platform?
I am using FMP11 under Snow Leopard
It would be easier if I could join the FMP file I am working on.
A button, when clicked, displays a pop-up menu which aloows the user to select one item among two : Print invoice, Order history Report.
The script activated once one item has been selected analyses the text of the selected item, to know wht to do.
How this script gets this text ?
Well Ninja is quite capable of answering but in case you'd like an answer sooner ...
You can attach script trigger to the field 'upon field exit' to run your process. Script might look like:
If [ pop-up field = "Print Invoice" }
Perform Script: Print Invoice
Else If [ pop-up field = Order History Report " ]
Perform Script: Order History Report
Show Custom Dialog [ "This field is empty or does not contain a value value" ]
Of course you could list your Print Invoice steps in place of the Perform Script; same with Order History Report.