(function(){
	if(!function.prototype.bind){
		function.prototype.bind = function(obj){
			var owner = this,args = array.prototype.slice.call(arguments),callobj = array.prototype.shift.call(args);
			return function(e){e=e||top.window.event||window.event;owner.apply(callobj,args.concat([e]));};
		};
	}
})();
var banner_tabs = function(id){
	this.ctn = document.getelementbyid(id);
	this.adlis = null;
	this.btns = null;
	this.animstep = 0.2;//�����ٶ�0.1��0.9
	this.switchspeed = 3;//�զ����ż��(s)
	this.defopacity = 1;
	this.tmpopacity = 1;
	this.crtindex = 0;
	this.crtli = null;
	this.adlength = 0;
	this.timeranim = null;
	this.timerswitch = null;
	this.init();
};
banner_tabs.prototype = {
	fnanim:function(toindex){
		if(this.timeranim){window.cleartimeout(this.timeranim);}
		if(this.tmpopacity <= 0){
			this.crtli.style.opacity = this.tmpopacity = this.defopacity;
			this.crtli.style.filter = 'alpha(opacity=' + this.defopacity*100 + ')';
			this.crtli.style.zindex = 0;
			this.crtindex = toindex;
			return;
		}
		this.crtli.style.opacity = this.tmpopacity = this.tmpopacity - this.animstep;
		this.crtli.style.filter = 'alpha(opacity=' + this.tmpopacity*100 + ')';
		this.timeranim = window.settimeout(this.fnanim.bind(this,toindex),50);
	},
	fnnextindex:function(){
		return (this.crtindex >= this.adlength-1)?0:this.crtindex+1;
	},
	fnswitch:function(toindex){
		if(this.crtindex==toindex){return;}
		this.crtli = this.adlis[this.crtindex];
		for(var i=0;i<this.adlength;i++){
			this.adlis[i].style.zindex = 0;
		}
		this.crtli.style.zindex = 2;
		this.adlis[toindex].style.zindex = 1;
		for(var i=0;i<this.adlength;i++){
			this.btns[i].classname = '';
		}
		this.btns[toindex].classname = 'cur'
		this.fnanim(toindex);
	},
	fnautoplay:function(){
		this.fnswitch(this.fnnextindex());
	},
	fnplay:function(){
		this.timerswitch = window.setinterval(this.fnautoplay.bind(this),this.switchspeed*1000);
	},
	fnstopplay:function(){
		window.cleartimeout(this.timerswitch);
	},
	init:function(){
		this.adlis = this.ctn.getelementsbytagname('li');
		this.btns = this.ctn.getelementsbytagname('cite')[0].getelementsbytagname('span');
		this.adlength = this.adlis.length;
		for(var i=0,l=this.btns.length;i<l;i++){
			with({i:i}){
				this.btns[i].index = i;
				this.btns[i].onclick = this.fnswitch.bind(this,i);
				this.btns[i].onclick = this.fnswitch.bind(this,i);
			}

		}
		this.adlis[this.crtindex].style.zindex = 2;
		this.fnplay();
		this.ctn.onmouseover = this.fnstopplay.bind(this);
		this.ctn.onmouseout = this.fnplay.bind(this);
	}
};
var player1 = new banner_tabs('banner_tabs');