Silly scripting

[GoDl1Kelol]

Okay, I've been trying to get a key to open a door for a century, here's my script


void OnStart()
{
AddUseItemCallback("", "keyfordoor", "mansion_2", "UsedKeyOnDoor", true);
SetEntityCallbackFunc("keyfordoor", "OnPickup");
}
void UsedKeyOnDoor(string &in asItem, string &in asEntity)
{
SetSwingDoorLocked("mansion_2", false, true);
PlaySoundAtEntity("", "unlock_door.snt", "mansion_2", 0, false);
RemoveItem("keyfordoor");
}
void OnPickup(string &in asEntity, string &in type)
{
SetEntityActive("monster", true);
ShowEnemyPlayerPosition("monster");
}

I entered it many times and it didn't work and now all of a sudden it shows up with an error 12:13 ERR: keyfordoor not declared
I could really use some help for this