[Scripting Question] Need help with form changing held item script

[ButreNoah]

So, I began a new pokemon game with essentials. I tried to make a script in v16.2 that makes my test pok?mon change his form when he has a specific item, with the extra effect of the defence or attack stats raising by 50. The problem is that I tried to use Arceus' Plate transformations. I also tried Giratina's Griseous Orb transformation. But when I tried it, It didn't work. This is my current script...

MultipleForms.register(:WHISCASH,{
"getBaseStats"=>proc{|pokemon|
   next if pokemon.form==0
   case pokemon.form
   when 2; next [110,78,123,60,76,121] # Armored
   when 3; next [110,128,73,60,126,71] # Weaponed
   else;   next                        # Normal
   end
},
"getForm"=>proc{|pokemon|
     next 2  if isConst?(pokemon.item,PBItems,:WHISCASHARMOR)
     next 3  if isConst?(pokemon.item,PBItems,:WHISCASHWEAPON)
     next 0
}
})

Whiscash is just a template for everything tryout. Also I need to use forms 2 and 3 for this, because it also has a mega. Can anyone smart help me out and explain what I did wrong?