Javascr ipt控制页面中显示十字光标，鼠标的地方就是十字光标的中心，会随着鼠标的移动而变化，想一想，什么时候可以用到十字光标呢？在一些射击游戏中，是不是需要这种效果呢？或者打枪瞄准的时候。因此可把本代码用到一些网页游戏的开发中。

-Javascr ipt control page shows the crosshairs, is the center of the cross where the mouse cursor will change as the mouse moves, think about it, when it can be used crosshairs? In some shooting games, are not required to this effect? Or fire a gun aimed at the time. Therefore, the code can be used to develop some of the game s web page.