```````````````````````````````````````````````````
相信很多人几个世纪前(夸张手法)就会做这个啦,为了方便
初学者,我还是搞了个教程,呵呵~
看不到图请进这个地方:http://images.eefoo.com/viewimage.jsp?filename=http://images.eefoo.com/upload/pic/2006/07/21/min/0721200601311321802070370156.gif