http://tech.sina.com.cn/digi/2005-07-19/1822667472.shtmlhttp://cache.baidu.com/c?word=%D0%D4%BC%DB%3B%B1%C8%2C%D7%EE%B8%DF%2C%CA%FD%C2%EB%3B%CF%E0%BB%FA&url=http%3A//www%2Ecssjb%2Ecom/viewthread%2Ephp%3Ftid%3D14651&b=12&a=0&user=baidu看一看,就知道了。