different colored background

In some of the posts I see users leave comments on different colored backgrounds when answering questions from other users of the site. How do I get my posts to use this shaded or different colored background!

Use (quote) and (/quote) - replace () with [].

Or (code) tags?

Thanks for the quick response Gfk! I hadn't expected a reply so quickly.
Actually, I had meant the the first suggestion, but second suggestion is nice as well!

Oh, BTW, while we're on the subject, some programmers that do use the (code) tags also use collapsible boxes with an (+) sign for lenghty segments of code. Do yo know how to do that?

I don't know how to do that, but if you have excessibly long code, you should use (codebox) tags:

This is very long. This is very long. This is very long. This is very long. This is very long. This is very long. This is very long. This is very long. This is very long.