iYD ('0' unlocked, '1' locked) means required key.
If key is not in inventory, first time, display this message
YOU NEED A GEM TO PASS if Locked Door is on MAPDOOR.
Display this message
THE DOOR IS LOCKED if Locked Door is on DOORT/DOORB.
If key is in inventory, display this message
THE GATE OPENS if Locked Door is on MAPDOOR else
THE DOOR OPENS.
iCounter tag target of object type 15.
Replace the MAPDOOR or DOORT/DOORB by first non-blocking map block at left, on trigger message.
In case that DOORT/DOORB, display annimation.
To do animation, iState is increase by 1, and space between DOORT/DOORB is iState * 2.
Locked door not remove trigger object.