好久都没有关注jQuery了，趁着这次 1.7.2 的发布，学点新东西
http://api.jquery.com/category/version/1.7/
1.7 带来的改变
Event APIs: .on() and .off()
统一并代替了.bind() 和 .delegate() 方法，下面是新老API的比较
$('a').bind('click', myHandler);
$('a').on('click', myHandler);
$('form').bind('submit', { val: 42 }, fn);
$('form').on('submit', { val: 42 }, fn);
$(window).unbind('scroll.myPlugin');
$(window).off('scroll.myPlugin');
$('.comment').delegate('a.add', 'click', addNew);
$('.comment').on('click', 'a.add', addNew);
$('.dialog').undelegate('a', 'click.myDlg');
$('.dialog').off('click.myDlg', 'a');
$('a').live('click', fn);
$(document).on('click', 'a', fn);
$('a').die('click');
$(document).off('click', 'a');
Better Support for HTML5 in IE6/7/8 jQuery.Callbacks() Toggling Animations Work Intuitively