window.onload=function(){
	var ul=document.getelementsbyclassname("index-ul")[0];
	var ol=document.getelementsbyclassname("index-ol")[0];
	var ali=ol.children;
	var cli=ul.children;
	cli[0].style.opacity=1;
	var now=0;//当前图片索引
	
	for(var i=0;i<ali.length;i++){
		var li=ali[i];
		li.index=i;
		li.onclick=function(){
			now=this.index;
			tab();
		}
	}
	
	
	//显示图片
	function tab(){
		for(var i=0;i<ali.length;i++){
			var li=ali[i];
			li.classname='';
			startmove(cli[i],{opacity:0});
		}
		ali[now].classname='selected';
		//ul.style.top=now*-320+'px';
		startmove(cli[now],{opacity:100});
	}
	
	function next(){
		now++;
		if(now==ali.length)now=0;
		tab();
	}

	var timer=setinterval(next,3000);
	var box=document.getelementsbyclassname('news-box')[0];
	box.onmouseover=function(){
		clearinterval(timer);
	}
	box.onmouseout=function(){
		timer=setinterval(next,3000);
	}
	
	function getstyle(obj,attr){
        if(obj.currentstyle){
            return obj.currentstyle[attr];
        }else{
            return getcomputedstyle(obj,null)[attr];
        }
    }
	function startmove(obj,json,fn){
	    clearinterval(obj.timer);
	    obj.timer=setinterval(function(){
	        var flag=true;
	        for(var attr in json){
	            var end=json[attr];
	            var start=getstyle(obj,attr);
	            if(attr=='opacity'){
	                start=math.round(parsefloat(start)*100);
	            }else{
	                start=parseint(start);
	            }
	            var speed=(end-start)/6;
	            speed=(speed>0)?math.ceil(speed):math.floor(speed);
	            if (attr=='opacity') {
	                obj.style[attr]=(start+speed)/100;
	                obj.style.filter='alpha(opacity'+(start+speed)+')';
	            } else{
	                obj.style[attr]=start+speed+'px';
	            };
	            if(start==end){
	                
	            }else{
	                flag=false;
	            }
	        }
	        if(flag){
	            clearinterval(obj.timer);
	            if(fn){
	                fn();
	            }
	        }
	    },60)
	}
}