//code ref http://www.cnblogs.com/rubylouvre/archive/2009/07/24/1529640.html //支持 多class搜索 ie:getElementsByClassName("classA classB") var getElementsByClassName = function (searchClass, node, tag) { var node = node || document; var tag = tag || "*"; if (document.getElementsByClassName) {//尽量用原生方法 var nodes = node.getElementsByClassName(searchClass),result = []; if (tag === "*") {//直接return return nodes; } else { for (var node in nodes) { if (node.tagName === tag.toUpperCase()) { result.push(node) } } return result } } else { var classes = searchClass.split(" "), elements = (tag === "*" && node.all) ? node.all : node.getElementsByTagName(tag), patterns = [], current, match; var i = classes.length; while (i--) { patterns.push(new RegExp("(^|\\s)" + classes[i] + "(\\s|$)")); } var j = elements.length; while (j--) { current = elements[j]; match = false; for (var pattern in patterns) { match = pattern.test(current.className); if (!match) break; } if (match) result.push(current); } return result; } }