var isie = (document.all) ? true : false;
var $ = function (id) {
	return "string" == typeof id ? document.getelementbyid(id) : id;
};
var class = {
	create: function() {
		return function() { this.initialize.apply(this, arguments); }
	}
}
var extend = function(destination, source) {
	for (var property in source) {
		destination[property] = source[property];
	}
}
var bind = function(object, fun) {
	return function() {
		return fun.apply(object, arguments);
	}
}
var each = function(list, fun){
	for (var i = 0, len = list.length; i < len; i++) { fun(list[i], i); }
};
//ie only
var revealtrans = class.create();
revealtrans.prototype = {
  initialize: function(container, options) {
	this._img = document.createelement("img");
	this._a = document.createelement("a");
	this._timer = null;//计时器
	this.index = 0;//显示索引
	this._onindex = -1;//当前索引
	this.setoptions(options);
	this.auto = !!this.options.auto;
	this.pause = math.abs(this.options.pause);
	this.duration = math.abs(this.options.duration);
	this.transition = parseint(this.options.transition);
	this.list = this.options.list;
	this.onshow = this.options.onshow;
	//初始化显示区域
	this._img.style.width = this._img.style.height = "100%"; this._img.style.border = 0;
	this._img.onmouseover = bind(this, this.stop);
	this._img.onmouseout = bind(this, this.start);
	isie && (this._img.style.filter = "revealtrans()");
	this._a.target = "_blank";
	$(container).appendchild(this._a).appendchild(this._img);
  },
  //设置默认属性
  setoptions: function(options) {
	this.options = {//默认值
		auto:		true,//是否自动切换
		pause:		1000,//停顿时间(微妙)
		duration:	1,//变换持续时间(秒)
		transition:	23,//变换效果(23为随机)
		list:		[],//数据集合,如果这里不设置可以用add方法添加
		onshow:		function(){}//变换时执行
	};
	extend(this.options, options || {});
  },
  start: function() {
	cleartimeout(this._timer);
	//如果没有数据就返回
	if(!this.list.length) return;
	//修正index
	if(this.index < 0 || this.index >= this.list.length){ this.index = 0; }
	//如果当前索引不是显示索引就设置显示
	if(this._onindex != this.index){ this._onindex = this.index; this.show(this.list[this.index]); }
	//如果要自动切换
	if(this.auto){
		this._timer = settimeout(bind(this, function(){ this.index++; this.start(); }), this.duration * 1000 + this.pause);
	}
  },
  //显示
  show: function(list) {
	if(isie){
		//设置变换参数
		with(this._img.filters.revealtrans){
			transition = this.transition; duration = this.duration; apply(); play();
		}
	}
	//设置图片属性
	this._img.src = list.img; this._img.alt = list.text;
	//设置链接
	!!list["url"] ? (this._a.href = list["url"]) : this._a.removeattribute("href");
	//附加函数
	this.onshow();
  },
  //添加变换对象
  add: function(siimg, stext, surl) {
	this.list.push({ img: siimg, text: stext, url: surl });
  },
  //停止
  stop: function() {
	cleartimeout(this._timer);
  }
};