@paul12345 : I do not know why the implementation is recursive. Maybe it always was, or it's the most elegant solution. About the double quote: No, it does not work on WiPy if you drop the double quote at the end of the search string. But you will have a match on machines with more memory, simply because the sample string (line) you are searching at does not contain the pattern mp3". B.T.W.: Shortening the string in line works on WiPy. Regards, Robert