设置CSS

//前台调用
var $ = function () {
	return new Base();
}

//基础库
function Base() {}

//创建一个数组，来保存获取的节点和节点数组
Base.prototype.elements = [];

//获取CLASS节点数组
Base.prototype.getClass = function (className, idName) {
	var node = null;
	if (arguments.length == 2) {
		node = document.getElementById(idName);
	} else {
		node = document;
	}
	var all = node.getElementsByTagName('*');
	for (var i = 0; i < all.length; i ++) {
		if (all[i].className == className) {
			this.elements.push(all[i]);
		}
	}
	return this;
}

//获取某一个节点
Base.prototype.getElement = function (num) {	
	var element = this.elements[num];
	this.elements = [];
	this.elements[0] = element;
	return this;
};

//设置CSS
Base.prototype.css = function (attr, value) {
	for (var i = 0; i < this.elements.length; i ++) {
		if (arguments.length == 1) {//获取属性
			if (typeof window.getComputedStyle != 'undefined') {//W3C
				return window.getComputedStyle(this.elements[i], null)[attr];
			} else if (typeof this.elements[i].currentStyle != 'undeinfed') {//IE
				return this.elements[i].currentStyle[attr];
			}
		}
		this.elements[i].style[attr] = value;//设置属性
	}
	return this;
}