> Thanks for responding > I get the same error." undefined method push for append" > Is push a predefined function in the array function library? Call them "methods". Array is a class that contains the "push" method. That means that *all* arrays necessarily have a push method defined. That's part of what the words "class" and "method" imply. You still haven't sent me a sample code that produces your error. I cannot help you until you do that. -- Daniel Carrera Graduate Teaching Assistant. Math Dept. University of Maryland. (301) 405-5137