javascript.js

$(".markdown_link").live("click", function(e) {
  $(this).next(".markdown_examples").slideToggle();
});

markdown.rb

<div class="formatting">
	            Use Markdown for formatting. <%= link_to "See examples.", "javascript:void(0)", :class => "markdown_link" %>
	            <div class="markdown_examples" style="display: none">
	              <table>
	                <tr>
	                  <td><pre>[Link](http://example.com/)</pre></td>
	                  <td><a href="http://example.com/">Link</a></td>
	                </tr>
	                <tr>
	                  <td><pre>*Italic*</pre></td>
	                  <td><em>Italic</em></td>
	                </tr>
	                <tr>
	                  <td><pre>**Bold**</pre></td>
	                  <td><strong>Bold</strong></td>
	                </tr>
	                <tr>
	                  <td><pre>
						* Listed
						* Items
	                  </pre></td>
	                  <td><ul><li>Listed</li><li>Items</li></ul></td>
	                </tr>
	                <tr>
	                  <td><pre>&gt; Block quote</pre></td>
	                  <td><blockquote><p>Block quote</p></blockquote></td>
	                </tr>
	                <tr>
	                  <td><pre>`Inline code`</pre></td>
	                  <td><code>Inline code</code></td>
	                </tr>
	                <tr>
	                  <td>
	                    <pre>
						``` ruby
						puts "code block"
						```
	                    </pre>
	                  </td>
	                  <td><%= markdown("``` ruby\nputs \"code block\"\n```").html_safe %></td>
	                </tr>
	              </table>
	            </div>
	          </div>

style.css

.formatting {
  font-size: 12px;
  margin: 8px 0;
}

.markdown_examples {
  margin-top: 5px;
}

.markdown_examples table {
  border-collapse: collapse;
}

.markdown_examples table td {
  border: solid 1px #CCC;
  padding: 2px 10px;
}

.markdown_examples .code_block {
  width: 200px;
}