javascript实现滚动图片

<div class="block">
<div class="title">
<strong>服务展示 </strong>
</div>
<div class="content" id="showroom">
<div class="wrapper index_footer_slide">
<div id="index_foot_slide">
<div id="in_index_foot_slide">
<div id="index_foot_slide1">
<asp:Repeater ID="repBottomPictures" runat="server">
<ItemTemplate>
<a href="">
<img src='<%#Eval("ImageUrl")%>' /></a>
</ItemTemplate>
</asp:Repeater>
</div>
<div id="index_foot_slide2">
<asp:Repeater ID="Repeater1" runat="server">
<ItemTemplate>
<div>
<a href="">
<img src='<%#Eval("ImageUrl")%>' /></a></div>
</ItemTemplate>
</asp:Repeater>
</div>
</div>
</div>
</div>
</div>
</div>

var speed=12; //数字越大速度越慢
var tab=document.getElementById("index_foot_slide");
var tab1=document.getElementById("index_foot_slide1");
var tab2=document.getElementById("index_foot_slide2");
tab2.innerHTML=tab1.innerHTML;
function Marquee(){
if(tab.scrollLeft<=0)
tab.scrollLeft+=tab2.offsetWidth
else{
tab.scrollLeft--
}
}
var MyMar=setInterval(Marquee,speed);
tab.onmouseover=function() {clearInterval(MyMar)};
tab.onmouseout=function() {MyMar=setInterval(Marquee,speed)};