function startMove(obj,json,fn){

var flag=true;//假设所有都到达目标值

clearInterval(obj.timer);

obj.timer=setInterval(function(){

for(var attr in json){

//1、取当前值

var icur=0;

if(attr=='opacity'){

icur=Math.round(parseFloat(getStyle(obj,attr))*100);

}else{

icur=parseInt(getStyle(obj,attr));

}

//2、算速度

var speed=(json[attr]-icur)/8;

speed=speed>0?Math.ceil(speed):Math.floor(speed);

//3、检测停止

if(icur!=json[attr]){

flag=false;

}

if(attr=='opacity')

{

obj.style.filter='alpha(opacity:'+attr+')';//针对iE

obj.style.opacity=(icur+speed)/100;

}else{

   obj.style[attr]=icur+speed+'px';

}

}

 if(flag)

 {

clearInterval(obj.timer);

   if(fn)

{

fn();

}  

  }

},30)

};

//获取样式

function getStyle(obj,attr){

//IE

if(obj.currentStyle){

obj.currentStyle[attr];

}else{ //FF

return getComputedStyle(obj,false)[attr];

}

}