//后兩個(gè)參數(shù)可省略
function (name, type, parent) {
            var tempElems = [];
            var pattern = new RegExp("(^| )" + name + "( |$)");
            var e = (parent || document).getElementByTagName(type || "*");
            for (var i = 0; i < e.length; i++) {
                if (pattern.test(e[i].className)) {
                    tempElems.push(e[i]);
                }
            }
            return  tempElems;
}