Hiding & unhiding items on push of a button

Question

Hello,
hope any one could help...
I have a Form with some items there...
for some purpose I want to make a button and when it will be pressed for the first time, it hides one item say 'A' and unhide second item 'B' (which was first not visible)..
and when the button is pressed again for the second time it then hides item 'B' and unhides item 'A' and this process continues on every push with both items hiding and unhiding on alternate push of the button..
For this i wrote the following coding on when button pressed trigger
:GLOBAL.DUMMY := GET_ITEM_PROPERTY('A',VISIBLE);
:GLOBAL.DUMMY := GET_ITEM_PROPERTY('B',VISIBLE);
IF      
:GLOBAL.DUMMY = 'B PROPERTY_TRUE' AND
:GLOBAL.DUMMY = 'A PROPERTY_FALSE'
THEN
SET_ITEM_PROPERTY('B',VISIBLE,PROPERTY_FALSE);
SET_ITEM_PROPERTY('A',VISIBLE,PROPERTY_TRUE);
ELSE
SET_ITEM_PROPERTY('B',VISIBLE,PROPERTY_TRUE);
SET_ITEM_PROPERTY('A',VISIBLE,PROPERTY_FALSE);
END IF;
this coding succesfully hides 'A' and unhides item 'B' on the first push but nothing happens when I press the button again...as i said above I wnat it to unhide 'A' and and hide 'B' on the second push and then this process follow with items 'A' and 'B' hide and unhide respectively on alternate pushes...
I would be grateful if some one helps me in solving this problem..
regards,
Sonali.

Answer 1

Look to see what value is returned by GET_ITEM_PROPERTY('B',VISIBLE). I doubt very much that it's 'B PROPERTY_TRUE'.
Furthermore, your second call overwrites the prior value in DUMMY so your IF statement is never going to be true....
...particularly in view of the the fact that you are testing for one variable to simultaneously be two different values. This is not Boolean Logic as we know it.
Your code works the first time because it executes the ELSE branch, but it will execute IF branch.
Be a smartie - never call your variables DUMMY.
Cheers, APC