There is another option that’s useful when dealing with small amounts of code, and that is to add four or more spaces in front of each line of code.
For example, using leading spaces (a blank line before the code is required too):
<p>Four leading spaces are before the <p> tag</p>
<p>Another line of code</p>
You can easily indent your code by four spaces by highlighting the code, and pressing the </> button in the toolbar at the top of the reply area.
We have some good info on displaying code that’s well worth taking a look at.