荧幕滚动效果

屏幕滚动效果
<div id="mar" style="height:100px;overflow:hidden;">
            <div id="mar1">
                <table style="margin-left:20px;height:100px;" border="0" cellpadding="0" cellspacing="0" >
                   <tr>
                           <td
                                onClick="top.openWidgetTable('<s:text name="BPO.AGENT.MODULE.AFFICHE"/>', '<%=contextPath %>/agent/toBulletin.action','book_01.gif')">
                                <s:text name="BPO.TASK.AFFICHE.AFFI1"/></td>
                       </tr>
                       <tr>
                           <td border="0" cellpadding="0" cellspacing="0" >
                    </table>
                    </div>
                  </div>
<script language="javascript">
//滚动插件
var timer = 5000;
var speed = 10;
var marInter = null;
var marTimer = null;
var mar1Height = O("mar1").offsetHeight;
var count = 0;
var marguee = function()
{
    if (count >= 25)
    {
        count = 0;
        clearInterval(marInter);
        marTimer = setTimeout(function(){
            marInter = setInterval(marguee, speed);
        }, timer);
        return;
    }
    count++;
    var mar = O("mar");
    if (mar.scrollTop - mar1Height >= 0)
    {
        mar.scrollTop -= mar1Height - 1;
    }else
    {
        mar.scrollTop++;
    }
   
}

O("mar").onmouseover = function(){
    clearInterval(marInter);
    clearTimeout(marTimer);
}
O("mar").onmouseout = function(){
    marInter = setInterval(marguee, speed);
}

function initMarguee()
{
    O("mar2").innerHTML = O("mar1").innerHTML;
    marInter = setInterval(marguee, speed);
}

</script>