everything in between those braces (called a "block") will be run over and over, as long as the boolean is true. a common error for beginners is to forget to change the while-condition somewhere in the loop, or have bad logic that never changes it, causing an infinite loop. Note that this loop could run 0 times, if the expression is false the first time we hit it - no line in that block will execute even once.
something you can try is to pepper the code with a bunch of println statements of your own. something like this: note the "spot 1" and "spot 2". there are two places where x can change, and you might want to know when one fires vs. the other.
then you can re-compile and run the code, and see exactly what happening. [ January 09, 2007: Message edited by: Fred Rosenberger ]