[SCRIPT] FATAL ERROR..... Script

[Sigvash]

FATAL ERROR: Could not load script file 'custom_stories/The Choice/custom_stories/TheChoice/maps/third.hps'!
main (12,14) : ERR : 'monsterdoorkey_1' is not declared

thats the error

this is the third.hps file

////////////////////////////
// Run when entering map
void OnEnter()
{
AddUseItemCallback("", "monsterdoorkey_1", "monsterdoor", "UsedKeyOnDoor", true);
}

void UsedKeyOnDoor(string &in asItem, string &in asEntity)
{
SetSwingDoorLocked("monsterdoor", false, true);
PlaySoundAtEntity("" , "unlock_door", "monsterdoor", 0, false);
RemoveItem(monsterdoorkey_1);
}
////////////////////////////
// Run when leaving map
void OnLeave()
{

}

Can someone help me?
Im very new to this