try this....I know this works but it may or may not be what you need....

Public gcVar

gcVar = ''

loForm.Show(1) && modal form

wait gcVar window && this will show you the correct return value

Unload event should set and return the value of gcVar

Procedure Unload
gcVar = 'test' && your code here
endproc

The point is to call the show method with (1) as above and to have your form return a value that is stored in a global variable (be sure to have a unique name so this variable doesn't get reset or changedc later on...or just release it if you don't need it)