Hopefully a simple question for the person who already knows the answer.

How do you prevent the default HTML form behavior where hitting the tab
key causes focus to shift to the next entity in the form? I want to make
it possible for the user to type tabs into the text area and submit that
text when entering "code examples". I can't seem to track down an answer
to the problem, though. At first I thought I could use some sort of onblur
handler on the textarea to suppress the behavior, then I found a few hints
that it could be done with CSS styling on the textarea, but nothing has
panned out as I've tried to track it down.