导语：如何实现JavaScript的DIV块来回滚动效果呢?下面是小编给大家提供的代码实现过程，大家可以参考阅读，更多详情请关注应届毕业生考试网。
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<p id="xx" style=" position:relative;left:100px;width:100px;height:50px;border: solid 1px red;">脚本之家</p>
<script type="text/javascript">
function ls(){
var p=true;//开关,true开,false关
var xx=lementById('xx');
var xxleft = parseInt();
var speed = 20;
var t=setInterval(rollRight,speed);
//向左移动
function rollLeft(){
if(p){
xxleft--;
= xxleft+'px';
if(xxleft <=0 ){
clearInterval(t);
t=setInterval(rollRight,speed);
}
}
}
//向右移动
function rollRight(){
if(p){
xxleft++;
= xxleft+'px';
if(xxleft >= 300){
clearInterval(t);
t=setInterval(rollLeft,speed);
}
}
}
}
ls();
</script>
</body>
</html>
