var myfocus={
 $:function(id){return document.getelementbyid(id);},
 $$:function(tag,obj){return (typeof obj=='object'?obj:this.$(obj)).getelementsbytagname(tag);},
 style:function(obj,style){return (+[1,])?window.getcomputedstyle(obj,null)[style]:obj.currentstyle[style];},//getstyle简化版
 easeout:function(t,b,c,d){return -c*((t=t/d-1)*t*t*t - 1) + b;},
 move:function(obj,prop,val,type,spd,fn){//运动函数，spd为运动需要的时间，时间越大速度越小
  var t=0,b=parseint(this.style(obj,prop)),c=val-b,d=spd||50,st=type,m=c>0?'ceil':'floor';
  if(obj[prop+'timer']) clearinterval(obj[prop+'timer']);
  obj[prop+'timer']=setinterval(function(){
   if(t<d){obj.style[prop]=math[m](myfocus[st](++t,b,c,d))+'px';}
   else {clearinterval(obj[prop+'timer']);fn&&fn.call(obj);}
  },10);return this;
 },
 addlist:function(obj,cla,x){//生成hmtl,cla为列表的class,其中封装有:cla='txt'(生成alt文字),cla='num'(生成按钮数字),cla='thumb'(生成小图)
  var s=[],n=x||this.$$('li',this.$$('ul',obj)[0]).length,num=cla.length;
  for(var j=0;j<num;j++){
   s.push('<ul class='+cla[j]+'>');
   for(var i=0;i<n;i++){s.push('<li>'+(cla[j]=='num'?(i+1):(cla[j]=='txt'?this.$$('li',obj)[i].innerhtml.replace(/\<img.*?\>/i,this.$$('img',obj)[i].alt):(cla[j]=='thumb'?'<img src='+(this.$$('img',obj)[i].getattribute("thumb")||this.$$('img',obj)[i].src)+' />':'')))+'<span></span></li>')};
   s.push('</ul>');
  }; obj.innerhtml+=s.join('');
 },
 setting:function(par){
  if(window.attachevent){window.attachevent('onload',function(){myfocus[par.style](par)});}
else{window.addeventlistener('load',function(){myfocus[par.style](par)},false);}
 },
 mf_liuzg:function(par){
  var box=this.$(par.id),boxh=box.offsetheight,t=par.time*1000;
  this.addlist(box,['txt-bg','txt','num']);
  var pic=this.$$('li',this.$$('ul', box)[0]),n=pic.length;
  var c=boxh%par.chip?8:par.chip,h=boxh/c,pics=[];
  for(var i=0;i<c;i++){
   pics.push('<li><p>')
   for(var j=0;j<n;j++) pics.push(pic[j].innerhtml);
   pics.push('</p></li>')
  }
  this.$$('ul', box)[0].innerhtml=pics.join('');
  var ul=this.$$('ul',box),txt=this.$$('li',ul[2]),btn=this.$$('li',ul[3]),pic=this.$$('li',ul[0]);
  for(var i=0;i<c;i++){//初始化样式设置
   this.$$('p',pic[i])[0].style.top=-i*h+'px';
   pic[i].style.height=h+'px';
   this.$$('p',pic[i])[0].style.height=boxh*c+'px';
  }
  var index = 0;//开始显示的序号
  box.removechild(this.$$('div',box)[0]);
  var run = function(idx) {
   var tt=par.type==4?math.round(1+(math.random()*(3-1))):par.type;//效果选择
   btn[index].classname = '';
   txt[index].style.display='none';
            if(index==n-1) index=-1;
   var n=idx!=undefined?idx:index+1;
   var spd=tt==2?20:(tt==1?80:math.round(20+(math.random()*(80-20))));
   for(var i=0;i<c;i++){
    if(tt==3) spd=math.round(20+(math.random()*(80-20)));
    myfocus.move(myfocus.$$('p',pic[i])[0],'top',-n*c*h-i*h,'easeout',spd);
    spd=tt==2?spd+10:(tt==1?spd-10:spd);
   }
   btn[n].classname = 'current';
   txt[n].style.display='block';
            index = n;
        }
  run(index);
  var auto=setinterval(function(){run()},t);
  for (var j=0;j<n;j++){
   btn[j].j=j;
   btn[j].onclick=function(){if(!this.classname) run(this.j)}
  }
  box.onmouseover=function(){clearinterval(auto);}
     box.onmouseout=function(){auto=setinterval(function(){run()},t);}
  for(var i=0,lk=this.$$('a',box),ln=lk.length;i<ln;i++) lk[i].onfocus=function(){this.blur();}//去除虚线框
 }
};
myfocus.setting({
 style:'mf_liuzg',//style为风格样式，
 id:'myfocus',//焦点图id
 chip:8,//图片切片数量，能被焦点图的高整除才有效，默认为8片
 type:2,//切片效果，1为甩头，2为甩尾，3为凌乱，4为随机效果
 time:4//每帧图片时间间隔
});