[protagonist]

Go to your Graal folder and open up commands.rtf. The things you will need are:

playerchats
strequals
show
hide

What these commands do:
playerchats
When the player chats, playerchats is true. It is what is called an event, meaning that when it is true anything in the following brackets, { } in the case of if(playerchats), will be "read" by the program and checked/performed.

strequals(string, condition)
Strequals checks if string (for example, #a, which is account name. See the bottom of commands.rtf for more info on built-in strings) is equal to condition. Conditionals, however, need to be included in an event or they are not read.

show
Show is what it sounds like. It makes the NPC visible.

hide
Hide is the opposite of show.



Hope this helps, I think it's more useful to help teach you to fish rather than give you fish.