Amnesia HPL Problem!

[Steve]

like what Chronofox said you have to put the ";" in the end of the line and not in front and you forgot to make some { and } so this should work:
void OnStart()
{
AddUseItemCallback("", "Key_1", "LockedDoor1", "UsedKeyOnDoor", true);
}

void UsedKeyOnDoor(string &in asItem, string &in asEntity)
{
SetSwingDoorLocked("LockedDoor1", false, true);
RemoveItem("Key_1");
}
and you also need quotations for LockedDoor1 and Key_1 which I included in my code.
I hope this helps