function startmove(obj, json, fnend)
{
	if(obj.timer)
	{
		clearinterval(obj.timer);
	}
	obj.timer=setinterval(function (){
		domove(obj, json, fnend);
	}, 30);
	
	var odate=new date();
	
	if(odate.gettime()-obj.lastmove>30)
	{
		domove(obj, json, fnend);
	}
}

function getstyle(obj, attr)
{
	if(obj.currentstyle)
	{
		return obj.currentstyle[attr];
	}
	else
	{
		return getcomputedstyle(obj, false)[attr];
	}
}

function domove(obj, json, fnend)
{
	var icur=0;
	var attr='';
	var bstop=true;	//假设运动已经该停止了
	
	for(attr in json)
	{
		if(attr=='opacity')
		{
			icur=parseint(100*parsefloat(getstyle(obj, 'opacity')));
		}
		else
		{
			icur=parseint(getstyle(obj, attr));
		}
		
		if(isnan(icur))
		{
			icur=0;
		}
		
		var ispeed=(json[attr]-icur)/8;
		ispeed=ispeed>0?math.ceil(ispeed):math.floor(ispeed);
		
		if(parseint(json[attr])!=icur)
		{
			bstop=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(bstop)
	{
		clearinterval(obj.timer);
		obj.timer=null;
		
		if(fnend)
		{
			fnend();
		}
	}
	
	obj.lastmove=(new date()).gettime();
}