// 获取对象的方法，可以根据传入单个ID来返回对象，
function $() {
    var elements = new Array();

    for (var i = 0; i < arguments.length; i++) {
        var element = arguments[i];
        if (typeof element == 'string')
            element = document.getElementById(element);

        if (arguments.length == 1)
            return element;

        elements.push(element);
    }

    return elements;
}