大半夜上来求助，请教一下怎么把这个js写成隐藏模式
谢谢啦。。。

function play() {
    var ps = document.documentElement.scrollTop < marginTop ? marginTop : document.documentElement.scrollTop;
    if(objY > ps) {
        objY -= moveSpeed;
        if(objY < ps) objY = ps;
    }
    else {
        objY += moveSpeed;
        if(objY > ps) objY = ps;
    }
    if(objL) objL.style.top = objY + "px";

}
var marginTop = 0; 
var marginSide = 0; 
var moveSpeed = 25; 
var objY = marginTop;
var objL = document.getElementById("kf");

var isUse = false;
if(objL) {
    objL.style.position = "absolute";
    objL.style.left = marginSide + "px";
    isUse = true;
}

if(isUse) setInterval(this.play,30);

[解决办法]
function play() {
var ps = document.documentElement.scrollTop < marginTop ? marginTop : document.documentElement.scrollTop;
if(objY > ps) {
objY -= moveSpeed;
if(objY < ps) objY = ps;
}
else {
objY += moveSpeed;
if(objY > ps) objY = ps;
}
if(objL) objL.style.top = objY + "px";

}
var marginTop = 0;
var marginSide = -30; ///////////自己依据宽度定义这个隐藏的内容宽度
var moveSpeed = 25;
var objY = marginTop;
var objL = document.getElementById("kf");

var isUse = false;
if(objL) {
objL.style.position = "absolute";
objL.style.left = marginSide + "px";
isUse = true;
objL.onmouseover=function(){objL.style.left='0px';}
objL.onmouseout=function(){objL.style.left = marginSide + "px";}
}

if(isUse) setInterval(this.play,30);