[NTG-context] Source and Result Side by Side

Hi all, I'm wondering how I can achieve the effect similar to that in books like The LaTeX Companion, where the source and the final result are placed side by side in two boxes. Thanks! Helin -- Helin (Colin) Gai Class of 2009, Duke University Box 96332 Durham, NC 27708 Phone: 919-943-6302 helin.gai at gmail.com hg9 at duke.edu