offsetTop,scrollHeight,scrollTop理解不是很清楚
<body>
<div id="colee_bottom" style="overflow:hidden;height:253px;width:410px; border:1px solid #000000">
<div id="colee_bottom1">
<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>
<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>
<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>
<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>
<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>
<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>
<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>
<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>
<p><img src="/jscss/demoimg/200907/bg3.jpg"></p>
</div>
<div id="colee_bottom2"></div>
</div>
<script>
var speed=30
var colee_bottom2=document.getElementById("colee_bottom2");
var colee_bottom1=document.getElementById("colee_bottom1");
var colee_bottom=document.getElementById("colee_bottom");
colee_bottom2.innerHTML=colee_bottom1.innerHTML
colee_bottom.scrollTop=colee_bottom.scrollHeight
function Marquee2(){
if(colee_bottom1.offsetTop-colee_bottom.scrollTop>=0)
colee_bottom.scrollTop+=colee_bottom2.offsetHeight
else{
colee_bottom.scrollTop--
}
}var MyMar2=setInterval(Marquee2,speed)
colee_bottom.onmouseover=function() {clearInterval(MyMar2)}
colee_bottom.onmouseout=function() {MyMar2=setInterval(Marquee2,speed)}
</script>
</body>
上面红色部分的代码有点理解不了,求解……