Hi Barry - so the thing where your new UI is flashing and going away is because the script currently just runs through and exits, and when it exits the command ends, and when the command ends the command UI is torn down and goes away.

So in order to make some UI appear and stay up there to interact with, you would need to modify the .js file as well, to make it go into an event loop instead of just running through and exiting. I'll also make an example for you.

- Michael