[Graphics] GRaphics & ASM Show image at map entrance with level script

[Shogun]

Hi !
I've been used this wonderful asm hack https://whackahack.com/foro/threads/lvl-script-mostrar-pantala-de-entrada-en-la-map.65950/ (in spanish)
This asm allows us to show an image, for example a fullscreen image when you arrive in a map.
The script :
'---------------
#org 0xF68B00
setvar 0x40F2 0x2 // the var here is set to a number in my table of graphics
callasm 0x8F68C01 //it calls the asm to show the image
pause 0x500 //duration
callasm 0x8F68C61 // Similar to the other ASM
end

If I affect this script to an NPC it works fine !
But if I affect it to the lvl script section in A-MAP header, It happens nothing. (I've set it to lvl script type 3)
What's wrong in my program ?

Thanks