When you design a Java program's graphical user interface for the first time, you may have trouble believing that it's an advantage for components to move around. There's an appeal to seeing something exactly in the way you designed it—a feature that's called WYSIWYG, an acronym for "What You See Is What You Get." Because Java was designed to run on a wide variety of operating systems and computing environments, interface layout was designed to be TNTWTMLL—There's No Telling What This Might Look Like. Layout managers provide a way to develop an attractive graphical user interface that is flexible enough to handle differences in presentation. During the next hour, you'll learn more about the function of a graphical user interface. You'll get a chance to see the LottoMadness interface in use as it churns through lottery drawings and tallies up winners.