用javascript实现动态浏览DataList中的内容

<div id="show" style="overflow: hidden; height: 122px;">
<asp:DataList ID="DataList1" runat="server" OnItemDataBound="DataList1_ItemDataBound"
Width="100%">
<ItemTemplate>
<table cellspacing="0" cellpadding="4" width="100%" border="0">
<tbody>
<tr>
<td class="black" style="width: 9%;">
<img src="images/LogImg6/images/qqlist2.gif" algin="middle" />
</td>
<td style="width: 66%;" valign="middle">
<a href="#" onclick="showWindow('news.aspx?topics=<%#Server.UrlEncode(Eval("topic").ToString()) %>&content=<%#Server.UrlEncode(Eval("content").ToString()) %>',300,500)">
<asp:Label ID="_lblContentnews" runat="server" Text='<%#Eval("topic") %>'></asp:Label></a>
</td>
<td>
<asp:Label ID="_lblNewsDate" runat="server" Text='<%#((DateTime)Eval("dates")).ToShortDateString() %>'></asp:Label>
</td>
</tr>
</tbody>
</table>
</ItemTemplate>
</asp:DataList>
</div>

<script type="text/javascript">
function startmarquee(lh, speed, delay) {
var t;
var oHeight = 122;
var p = false;
var o = document.getElementById("show");
var preTop = 0;
o.scrollTop = 0;
function start() {
t = setInterval(scrolling, speed);
o.scrollTop += 1;
}
function scrolling() {
if (o.scrollTop % lh != 0 && o.scrollTop % (o.scrollHeight - oHeight - 1) != 0) {
preTop = o.scrollTop;
o.scrollTop += 1;
if (preTop >= o.scrollHeight || preTop == o.scrollTop) {
o.scrollTop = 0;
}
} else {
clearInterval(t);
setTimeout(start, delay);
}
}
setTimeout(start, delay);
}
var isgun = "<%=count%>";
if(isgun>5)
startmarquee(25, 20, 1500);
</script>