Merge pull request #2 from hoosin/master

$.isNumeric改成 !NaN 兼容低版本jquery lib
fixed parent has position relative
update
1.5
1.6 add bottom and active className
support resize and add 3 more options, fixed ie6,and also add a liter version 1.4.js, it maybe the last version
Merge pull request #1 from kujian/master

update