Possible Duplicate:
How do I mark code blocks?
I'm new user here and my English is poor. So when I was putting one question here, a person told me that I needed to use some codes to show better my doubts. How should I write the code here for it to appear this way? 
Unfortunately I am writing and putting this way: bla-bla-bla
\documentclass[notes=show,12pt]{beamer} \usepackage{beamerthemeshadow} etc, ....
because I did't understand yet the help and the correct way. Thanks