Comments write to the comments div as plain text

comments.php retrieves the comments from the database, formats them into HTML,
and echos them.  The Javascript then appends this HTML to the comments div.
Specified id for script tag so comments.php can be easily referenced

Specified an id for comments.js's script tag so that it can be gotten via getElementByID().
Created a path variable to the directory in which comments.js is located by getting it by
id and getting its src attribute, then removing "comments.js".  Prepended the path variable
to all references to comments.php.