The green frame hopefully makes navigation simpler. No matter what page you are on, you can get to any other page by using the drop-down menus. The first menu contains categories of pages. Once a category is selected, the second drop-down menu shows the pages in that category. Clicking the "GO" button will load the selected page right here.
Here is an example that goes to Lesson 5:
The starting page is irrelevant...
... a category is selected (lessons of Part I)...
... a lesson is selected (Lesson 5)...
... the "GO" button is clicked and the page has loaded.
To go to the next page, click "Next". To go to the previous page, click "Back". The "Next" and "Back" links work for any page. To get back to the main page, click "Home".
Links from one lesson to another exist sometimes within pages themselves. These links are blue. Unfortunately, the frame at the top does not change accordingly when a link is followed.
Some links on the website are green. These links will work, eventually, to bring up a window with the definition of the linked word.