js不间断滚动

CSS

ul, li {
           margin: 0;
           padding: 0;
       }
 
       #scrollDiv {
           width: 300px;
           height: 25px;
           line-height: 25px;
           border-bottom: #4c8cd1 1px solid;
           overflow: hidden;
       }
 
           #scrollDiv li {
               height: 25px;
               padding-left: 10px;
           }

<script>
     function AutoScroll(obj) {
         $(obj).find("ul:first").animate({
             marginTop: "-25px"
         }, 800, function () {
             $(this).css({ marginTop: "0px" }).find("li:first").appendTo(this);
         });
     }
 
     $(document).ready(function () {
         setInterval('AutoScroll("#scrollDiv")', 3000)
         setInterval('AutoScroll("#scrollDiv")', 3000)
     });
 </script>

　　HTML

<div id="scrollDiv">
                <ul>
                    <li>这是公告标题的第一行</li>
                    <li>这是公告标题的第二行</li>
                    <li>这是公告标题的第三行</li>
                    <li>这是公告标题的第四行</li>
                    <li>这是公告标题的第五行</li>
                    <li>这是公告标题的第六行</li>
                    <li>这是公告标题的第七行</li>
                    <li>这是公告标题的第八行</li>
                </ul>
                
            </div>