缓冲运动框架

//末尾有获取当前样式的方法
function startMove(obj,json,endFn){
        clearInterval(obj.timer);
        obj.timer = setInterval(function(){
            var bBtn = true;
            for(var attr in json){
                var iCur = 0;
                if(attr == 'opacity'){
                    if(Math.round(parseFloat(getStyle(obj,attr))*100)==0){
                    iCur = Math.round(parseFloat(getStyle(obj,attr))*100);
                    }
                    else{
                        iCur = Math.round(parseFloat(getStyle(obj,attr))*100) || 100;
                    }    
                }
                else{
                    iCur = parseInt(getStyle(obj,attr)) || 0;
                }
                
                var iSpeed = (json[attr] - iCur)/8;

            iSpeed = iSpeed >0 ? Math.ceil(iSpeed) : Math.floor(iSpeed);    
                if(iCur!=json[attr]){
                    bBtn = false;
                }
                if(attr == 'opacity'){
                    obj.style.filter = 'alpha(opacity=' +(iCur + iSpeed)+ ')';
                    obj.style.opacity = (iCur + iSpeed)/100;
                }
                else{
                    obj.style[attr] = iCur + iSpeed + 'px';
                }
            }
            
            if(bBtn){
                clearInterval(obj.timer);
                
                if(endFn){
                    endFn.call(obj);
                }
            }
            
        },30);
    }
//获取当前样式    
    function getStyle(obj,attr){
        if(obj.currentStyle){
            return obj.currentStyle[attr];
        }
        else{
            return getComputedStyle(obj,false)[attr];
        }
    }