When we wrote the three versions of the SYSMETS program in Chapter 2, we didn't know anything about the keyboard. We were able to scroll the text only by using the mouse on the scroll bars. Now that we know how to process keystroke messages, let's add a keyboard interface to SYSMETS. This is obviously a job for cursor movement keys. We'll use most of the cursor movement keys (Home, End, Page Up, Page Down, Up Arrow, and Down Arrow) for vertical scrolling. The Left Arrow key and the Right Arrow key can take care of the less-important horizontal scrolling.