Slow in - Slow out

speed = 10;
rate =0;
_root.onEnterFrame = function(){
//등
box._x=box._x+speed;
...if(box._x>위치){
speed = 0;
}
//감
box._x=box._x+(위치-box._x)*0.15;
//동
rate=(500-box._x)*0.4+rate*0.7;
box._x = box._x+rate