App with on run and on idle not working

The on idle seems to not be called.

on idle
	display dialog "A wrinkle in time!"
	return 5
end idle

on run
	-->starts the app
	display dialog "I'm running!"
end run

Am I doing something wrong?

Did you check ‘stay open after run handler’ at the bottom of the Save dialog?
And maybe put an activate me in the idle handler, to make sure the dialog comes to the front.