Thank you, Wolfgang, this works better. Actually I need to use '%' in the condition and that fails: --- ... \startrawsetups layer % The value of 'n' is used here to set the appropriate background, % = n-th page of a PDF, and also to draw a filled rectangle on % the left or right side (depending on whether n is even or odd) % The code bellow fails \startluacode print("N=", n) if n % 2 == 1 then else end \stopluacode \stoprawsetups ... --- with: --- ! LuaTeX error <main ctx instance>:1: 'then' expected near 'else'. --- So like '%' was still treated as TeX comment char. How to enable '%'? Best regards, Lukas NB: Dirty trick: to define a Lua function like 'function isEven(n) return n % 2 == 0 end' and to use this function at the place of 'n % 2 == 1'; but I'd rather avoid this. -- 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