Description:
This example implements a Dialog Box like the 1,2,3-Button Dialog boxes from LabVIEW. The key difference is that it allows its calling VI to keep running in the background.
Other implementations are definitely possible, such as polling the Front Panel status of the popup VI, but the implementation uses a Start Asynchronous Call to start the VI running the the background. The User events help prevent race conditions and also show how you can use them across VIs.
Instructions:
I have converted it back to LabVIEW 2011 (also have LabVIEW 2012 SP1 attached) due to Start Asynchronous Call not in earlier LabVIEW versions. A similar Run VI method would work, but the User Event queues would have to be passed differently.
Example code from the Example Code Exchange in the NI Community is licensed with the MIT license.