//后两个参数可省略
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;
}