[NTG-context] (Ctx)Lua, diacritics & string.upper()

Hello, is there a possibility to use Ctx Lua to convert strings containing diacritics to upper/lower case? I have a .cld file, UTF-8, and ("Přehledná"):upper() gives "PřEHLEDNá" whilst the desired result is "PŘEHLEDNÁ". Is there a way how to solve this? (Maybe another function than Lua's "string.upper()".) Kind regards, Lukas -- Ing. Lukáš Procházka [mailto:LPr@pontex.cz] Pontex s. r. o. [mailto:pontex@pontex.cz] [http://www.pontex.cz] Bezová 1658 147 14 Praha 4 Tel: +420 244 062 238 Fax: +420 244 461 038