(1) 在屏幕上绘制一个矩形，并将举行内部划分成 4 个矩形区域；

(2) 在矩形内移动鼠标时，在上面划分的 4 个区域中显示不同的光标，并在屏幕左上角显示光标坐标；

(3) 当用户按下 SHIFT 和 CTRL 键并移动鼠标时，显示一个消息框，提示用户按下的是哪个键。

-(A) Draw a rectangle on the screen, and will hold internally divided into four rectangular areas　(2) move the mouse inside the rectangle in the above four areas divided display different cursor, and the upper left corner of the screen display cursor coordinates　(3) when the user presses the SHIFT and CTRL key and move the mouse to display a message box that prompts the user which key is pressed.