This site uses a contextual comment system to help us gather targeted feedback about the book. Instead of commenting on an entire chapter, you can leave comments on any individual "block" in the chapter. A "block" with comments looks like this:
The balloon shows the number of comments on that block.
A "block" is a paragraph, list item, code sample, or other small chunk of content. It'll get highlighted when you select it:
To post a comment on a block, just click in the gutter next to the bit you want to comment on:
Many, many thanks to Jack Slocum;
the inspiration and much of the code for the comment system comes from Jack's
blog, and this site couldn't have been built without his wonderful
YAHOO.ext library. Thanks also to Yahoo for YUI itself.