https://github.com/wayou/sliphover/
https://github.com/webmandesign/jquery.hoverdir/blob/master/jquery.hoverdir.js
http://www.cnblogs.com/lyzg/p/5689761.html
https://segmentfault.com/q/1010000006144675?_ea=1032446
https://github.com/wayou/sliphover/
https://github.com/webmandesign/jquery.hoverdir/blob/master/jquery.hoverdir.js
http://www.cnblogs.com/lyzg/p/5689761.html
https://segmentfault.com/q/1010000006144675?_ea=1032446