The pop-up menu activated by pressing the ``M'' icon on the tool bar at the right of each window is called the mark menu. In TeX mode (and other modes as well), the mark menu gives an outline of the current document and provides a way to quickly navigate a long file. Simply press the ``M'' icon and choose the Mark File command. The contents of the current document will be scanned and the titles of all chapters, sections, and subsections will be placed on the menu. Files that are \include'd or \input'ed will also appear on the mark menu. Note that the mark menu is static, that is, if you change the structure of the current document, you must choose the Mark File command again.
Note: Currently, there is considerable overlap between the funcs menu and the mark menu in terms of functionality. This will change in future versions of Alpha.