Navigation Help

Hypertext Links

You are looking at HyperText documents. The colored and/or underlined text ( for example, like this ) corresponds to hypertext links to other documents. Clicking once on these links will take you to the corresponding document, and if you use the mouse to place the cursor over the link the corresponding address for the link usually appears somewhere on the screen (Often at the bottom, but exactly where depends on the browser you are using---hold your mouse over a link without clicking and see what happens!).

HyperText is for exploring, and you are unlikely to get into trouble by clicking on whatever link interests you. You can always return to the previous page by using the "Back" button on your browser, and your browser probably has a "History" list that allows you to return immediately to documents accessed earlier in the session. In the worst case, the "Home" button on the browser will rescue you from almost anything, taking you back to where you started. And don't worry about damaging any hardware or software on your computer by randomly clicking on links. If you can do that, you are very clever indeed!

Browser Navigation Buttons

Exactly where these navigation buttons are located depends on your browser. The following image shows the menu of Netscape Navigator 1.1N for Unix. The "Back" button, as well as other navigation aids such as "Home" and "Forward" (you guessed it, the opposite of "Back"!) are evident. The "History" list in this case is a pulldown menu under "Go". Your browser is probably similar. Note that this is an IMAGE OF A BROWSER, not a browser---you can't click on the buttons in this image and expect it to do anything!)

Most browsers are very intuitive, so just click on things to see what they do. If you don't like what they do, use the "Back" button and try something else!

Visited and Unvisited Links

If your browser is set up to distinguish visited from unvisited links, the color of links you have already visited will be different from unvisited ones. The exact colors depend on your browser and the document you are viewing. Two common colors for visited and unvisited links are red and blue, respectively, but they depend on the browser and how the document that you are viewing has been written. For example, in the present document the visited and unvisited links will probably be green and yellow, respectively, if you are using Netscape Navigator as your browser.

Additional Navigation Buttons

At the bottom of main pages there may be additional navigation buttons, as illustrated in the following image (some of these buttons may not be present on a particular page).

Clicking on the right-arrow button (or the word "Next") will take you to the next section; the left arrow (or "Back") returns to the previous section; the up arrow (or "Top") takes you to the top of the present page; the Home button (or "Home") takes you to the entry level for this module (the Table of Contents---note that this "Home" is generally different than the corresponding one on the browser itself), and the "Help" button gives you help information such as what you are reading now.

Images as Hypertext Links

In addition to words, other objects on a page may be clickable links. For example, images may be hypertext linked to something else. This will usually be indicated by a colored box around the image, or by some other signal (for example, in Netscape Navigator the cursor image turns into a hand with a pointing finger when it is over a clickable link). When in doubt, click and see what happens!

Browser Frames

Newer browsers have the capability to divide the main browser window into several sub-windows or "frames". The adjacent figure illustrates for a screen divided into 4 frames. Essentially, each frame is an independent browser window, and these independent browser windows can talk to each other.

Frame Navigation

If you are already familiar with normal browser operation, there is one important feature of frames that you must keep in mind: the "Back" and "Forward" buttons may not work within each frame in the normal way. These buttons normally refer to the ENTIRE BROWSER DISPLAY, but remember that each frame essentially is a separate browser.

To go forward or backward within a frame (for example, in the one you are reading now) you should put the mouse cursor over the frame and hold the button down (try it on this frame). This will give a popup window that has as options "Back in Frame" and "Forward in Frame". These commands behave like the "Back" and "Forward" buttons for that frame. Generally, other browser options behave as in non-frame documents, except that they may refer only to a single frame. For example, the "Back" and "Forward" buttons for the full browser may update individual frames (e.g., in Netscape 3.0), or the entire frame display (e.g., in Netscape 2.0); test it with your browser and see. However, the mouse technique described above should work with all browser versions supporting frames. (Note that for multibutton mice the preceding mouse instructions may apply to the right button for 2-button PC and 3-button Unix mice; try it and see.)

Home         (Use the "Back" function with the mouse to return)