NPC Code:
if (playerchats&&strequals(#c,open sesame)) {
hide; // here we hide the door if the player says "open sesame"
dontblock; // this makes it so the passage doesn't block the player even when it's hiding
timeout = 5;
}
if (timeout) {
show; // this will show the door (secret passage blocker) again
blockagain; // this will block the passage again.
}
Now, if it's for an NPC Server, it's a whole different story, but you could probably get away with putting
//#CLIENTSIDE in front of the whole script.