Scripts

I recently started learning scripting, and even the simplest scripts that are explained multiple times cause difficulties, but I think I've figured it out.
I need help with this.
I can't understand how to use the "ShowFlyingSign" command correctly:

function offlich()
Trigger(REGION_ENTER_AND_STOP_TRIGGER, "off", nil);
ShowFlyingSign(GetMapDataPath().."offli.txt");
end;
Trigger(REGION_ENTER_AND_STOP_TRIGGER, "off", "offlich");

Also, can I add "PLAYERFLT_1" to "ShowFlyingSign"?
Since I'm creating a multiplayer map, I want the message to be displayed to the first player. I used this:

function mostFF()
Trigger(REGION_ENTER_AND_STOP_TRIGGER, "most", nil);
MessageBoxForPlayers(PLAYERFLT_1, GetMapDataPath().."most11.txt");
end;
Trigger(REGION_ENTER_AND_STOP_TRIGGER, "most", "mostFF");