I'm solving this like this on my server (in my case english and german):
prontera,146,174,4 script Translator#tr01::Translator 727,{
mes "[Translator]";
mes " * Please choose a language";
mes " * Bitte wähle eine Sprache";
next;
menu "English",-,"German",L_Ger;
set #language,0;
next;
mes "[Translator]";
mes "Thank you.";
mes "Have fun on " + $server_Name$ + ".";
close;
L_Ger:
set #language,1;
next;
mes "[Translator]";
mes "Danke.";
mes "Viel Spaß auf " + $server_Name$ + ".";
close;
}
And then make my NPC's multilanguage like this:
if (#language == 1) {
mes "Wo möchten sie hin?";
} else {
mes "Where do you want to go?";
}