Detect if form is already being displayed

This is how I do it:

defun( xxxx ()
 prog((xxxx)
  when(boundp('my_form) && axlIsFormType(my_form) && axlUIWExpose(my_form), return())
  defvar(my_form)

...

Thanks Dave. Can you please explain what these lines are doing? And, this is part of the same Skill script that invokes the form...?

I just showed the defun and prog lines to show that you need to include the lines in a prog loop to be able to use return(). You can, of course, exit more cleanly than this if you object to using return().
declaring myForm as global using defvar ensures that you can detect if it's called later.
boundp('my_form) tells you whether the form has been used before in this session.
axlIsFormType(my_form) tells you whether the form is still active (it will be nil if not).
If it is active, axlUIWExpose(my_form) exposes the form and return() exits the function.

Thanks Dave - appreciate the help very much.