Note - you must have an account on hydrolab for this to work.
If you do not give a document name in the URL, the Web server will look for a document named index.html - if there is not one by that name, a directory list will be shown. To ensure no directory list can be seen, create a html document with the name index.html
For examples of how to create html documents, check out the files in /home/rparry/public_html. I also am trying to maintain a list of HTML reference material