This site navigation page uses the same Master XML File with a different XSL file. The structure in this case is two-level, with a static list of the main sections in the left column, and two dynamic columns (center and right) displaying the sub-sections and the description of the selected section.

Moving the mouse cursor over the menu items displays the description of the corresponding item in the status bar. Clicking one of the main sections updates both the sub sections (center column) and the main subject description (right hand column). Clicking one of the sub sections loads the corresponding page. Use the browser's Back button to return to this menu.