different titles for different copies while printing an invoice

hi guys !!

I want to print different titles on copies as follows...

1st copy - "Original"

2nd copy - "Duplicate"

3nd copy - "Triplicate"...

i have used system vairable SFSY-COPYCOUNT....

in my 'Copies Window'..i have the following program lines..

CASE SFSY-COPYCOUNT.

WHEN 1.

TEXT = 'Original'.

WHEN 2.

TEXT = 'Duplicate'.

WHEN 3.

TEXT = 'Triplicate'.

ENDCASE .

but the problem is this variable is always 001.....

i guess all the variables are initialised when ever the next copy is printed....

any idea why????

thnx ....