This command lets you call up a function NPC. A function NPC can be called from
any script on any map server. Using the 'return' command it will come back to
the place that called it.

place,50,50,6%TAB%script%TAB%Woman%TAB%115,{
mes "[Woman]"
mes "Lets see if you win";
callfunc "funcNPC";
mes "Well done you have won";
close;
}
function%TAB%script%TAB%funcNPC%TAB%{
set @win, rand(2);
if(@win==0) return;
mes "Sorry you lost";
end;
}

You can pass arguments to your function - values telling it what exactly to do -
which will be available there with getarg() (see 'getarg')
Notice that returning is not mandatory, you can end execution right there.

If you want to return a real value from inside your function NPC, it is better
to write it in the function form, which will also work and will make the script
generally cleaner:

place,50,50,6%TAB%script%TAB%Man%TAB%115,{
mes "[Man]"
mes "Gimme a number!";
next;
input @number;
if (callfunc("OddFunc",@number)) mes "It's Odd!";
close;
}
function%TAB%script%TAB%OddFunc%TAB%{
if (getarg(0)%2==0) goto ItsEven;
return (1);
ItsEven:
return (0);
}