If the user re-shows the form using the show command then the system will attempt to demand load the definition again. This is slow and expensive if the user has not modified the definition so avoid it: use
loadform !!MyForm and
!!MyForm.show() instead.
If the user executes a layout form !!MyForm... while the form
!!MyForm already exists then it is killed and a new definition is started. This mechanism may be useful because it makes it possible to generate a form definition interactively from within their AppWare.