Why my Printpapersize has no effect? (bouhouhou Š )

[Fran=?ISO-8859-1?B?5w==?=ois Cuneo]

Hello!
I have some problems with PrintPapersize.

In fact, if the Print setup Dialog is US Letter (by ex), my PrintPaperSize
has no effect!

I know that if I open the setup dialog, it's normal (you have to restard the
application), but I don't do that.

So here is my code (I have 3 radio button on my card)

if the hilite of cd btn "US Letter" is true then
    put 612 into largeur
    put 792 into hauteur
    put 31 *2into nbquestparpage
    put "printus" into fenimpr
  else
  if the hilite of cd btn "A5" is true then
      put 540 into largeur
      put 410 into hauteur
      put 16 *2 into nbquestparpage
      put "printa5" into fenimpr
    else
      put 541 into largeur
      put 855 into hauteur
      put 35 *2 into nbquestparpage
      put "printa4" into fenimpr
    end if    
  end if   

 go to stack fenimpr
 set the printpapersize to largeur,hauteur
 set the printmargins to 17,17,17,17
 open printing with dialog as sheet
 if it is cancel then
   close printing
 else      
   print card 1 of stack fenimpr
End if
       
      
      WHAT IS WRONG PLEASE?