(2)　　弹球程序。编写程序，该程序通过一个发射按钮可以发射一个弹球，该球遇到边界时会自动弹回，在移动固定次数后，该球停止运动。要求每次点击发射按钮都会发射一个弹球，如果点击多次，则多个弹球同时运动。该程序通过另一个结束可以结束程序的运行-(2) pinball program. Programming, the program can be launched via a launch button of a ball, the ball met the boundary will automatically jump back on the move after a fixed number of times the ball stop. Requirements of each click the launch button will launch a ball, if you click several times, the same number of ball movement. The end of the program through another run to end the program