JavaScript封装动画函数然后分别调用时出现的问题

[Luminous116]

效果出现这种情况，下面附代码，求助大牛们，代码哪里要修改一下

function $(id) {
            return document.getElementById(id);
        }
        function animate(obj,target) {
            var timer;
            var left = obj.offsetLeft;
            var speed = left > target ? -1 : 1;
            timer = setInterval(function() {
                left = left + speed;
                obj.style.left = left + "px";
                if(left == target) {
                    clearInterval(timer);
                }
            },1)
        }
        window.onload = function() {
            $("one").onmouseover = function() {
                //debugger;
                animate(this,0);
                $("one").onmouseout = function() {
                    animate(this,-88);
                }
            };

            $("two").onmouseover = function() {
                //debugger;
                animate(this,0);
                $("two").onmouseout = function() {
                    animate(this,-88);
                }
            }

        }

[天际的海浪]

        function animate(obj,target) {
            var left = obj.offsetLeft;
            var speed = left > target ? -1 : 1;
            clearInterval(obj.timer);
            obj.timer = setInterval(function() {
                left = left + speed;
                obj.style.left = left + "px";
                if(left == target) {
                    clearInterval(obj.timer);
                }
            },1)
        }