Haha cool, i was thinking that somehow calling string.find() using C api might be possible solution... not super elegant, but much more reasonable than using C regexp library just for this one thing...I have lua embedded in system where users can define table of variables andUp to reserved words, the Lua pattern "^[%a_][%w_]*$" should do the job.then write expressions to process them. However i think it would bereasonable to have some sanity checks in place, so i don't have to explain why formulas using variable called "TIME-MAX" are not working :-) and stufflike that...-- Roberto
T. -- S pozdravem Best regards Tomáš Mudruňka - SPOJE.NET s.r.o.