【JS速度动画】选中框的代码的+10+那里，发现将10换成其他数字（比如7），为什么div的运动就会超出我设的限制条件的无限持续下去
<html>
<head>
<meta charset="utf-8">
<style>
#div1 {
width: 380px;
height: 247px;
left: -380px;
top: 0px;
position: absolute;
border: 1px solid #ccc;
background: green;
-moz-border-radius: 10px;
-webkit-border-radius: 10px;
border-radius: 10px;
-moz-box-shadow: 0 0 8px #000;
-webkit-box-shadow: 0 0 8px #000;
box-shadow: 0 0 8px #000;
}
#span1 {
width: 30px;
height: 80px;
left: 380px;
top: 168px;
position: absolute;
background: #567;
-moz-border-radius: 10px;
-webkit-border-radius: 10px;
border-radius: 3px;
-moz-box-shadow: 0 0 8px #000;
-webkit-box-shadow: 0 0 8px #000;
box-shadow: 0 0 8px #000;
}
#p1 {color: #fff;}
</style>
</head>
<body>
<div id="div1"><span id="span1"><p id="p1">分享到</p></span></div>
<script>
//加载即运行的始祖根函数
window.onload=function()
{
var div1=document.getElementById("div1"),
span1=document.getElementById("span1")
timer=null
div1.onmouseover=function()
{
startMove();
}
function startMove()
{
clearInterval(timer)
timer=setInterval(function()
{
div1=document.getElementById("div1")
if(div1.offsetLeft==0)
{clearInterval(timer);}
else
{div1.style.left=div1.offsetLeft+10+'px';}
},30)
}
}
</script>
</body>
</html>
