If I understand correctly you don't want to use multiple keys on one door just different keys for each door so scripting is unnecessary.
Simply change the key name (Key 1,Key 2 etc) and enter the name in the related door 'Use Key' properties, this door will then only open with the named key. You can name your keys whatever you like without messing with scripts.
I believe I saw somewhere that Lee had agreed to reintroduce the 'ifused' field which again will negate any messing around with scripts and simply enter a name for the entity to be triggered, it's the whole purpose of this software is to make it easy.
Why walk a mile when the shortest route from A to B is one simple step.
A funny thing happened on the way to the forum...