How to set artwork size in function

[l3m35]

I'm doing a multi system emulator, and since SNES have those horizontal art boxes, I need to reorganize some elements, like artwork position/size, overview position, etc, when user changes the emulator.

I was trying something like this:

Code: [Select]

function change_boxart( ){
if(fe.game_info(Info.Emulator) == "Super Nintendo") {
values <- "flw*0.297,flh*0.278, flw*0.235,flh*0.304"
}
else {
values <- "flw*0.297,flh*0.278, flw*0.235,flh*0.604"
}
}
local boxart = fe.add_artwork( "flyer",!change_boxart)
This is not the way ("wrong number of parameters"). Any clue or better idea about how to get all values from the function? Thanks!