javascript不能写在 .aspx 主页里面吗？总是说缺少对象~~求哥哥姐姐教育~···

想做个滚动的广告切换 方式都一样，只是写的页面不一样，一个是写在首页 Default.aspx里面 运行就报错，“缺少对象”；然而把这些写在另外的页面 Login.aspx 里面又却可以，怎么破啊？？~·求救了~~·/************报错的主页 Default.aspx 报错："缺少对象"**************/
<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="../App_Themes/DefaultPage/MainJS.JS" type="text/javascript"></script>
</head>
<style type="text/css"> 
.container, .container img{width:280px; height:200px;}
.container img{border:0;vertical-align:top;}
.container ul, .container li{list-style:none;margin:0;padding:0;}
 
.num{ position:absolute; right:5px; bottom:5px; font:12px/1.5 tahoma, arial; height:18px;}
.num li{
float: left;
color: #d94b01;
text-align: center;
line-height: 16px;
width: 16px;
height: 16px;
font-family: Arial;
font-size: 11px;
cursor: pointer;
margin-left: 3px;
border: 1px solid #f47500;
background-color: #fcf2cf;
}
.num li.on{
line-height: 18px;
width: 18px;
height: 18px;
font-size: 14px;
margin-top:-2px;
background-color: #ff9415;
font-weight: bold;
color:#FFF;
}
</style>
<body>
    <form id="form1" runat="server">
    <div>
    
<div class="container" id="idContainer2">
<ul id="idSlider2">
<li><a href="http://www.cnblogs.com/cloudgamer/archive/2009/12/22/ImagePreview.html"> <img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_song1.jpg" alt="图片上传预览" /> </a></li>
<li><a href="http://www.cnblogs.com/cloudgamer/archive/2009/08/10/FixedMenu.html"> <img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_song2.jpg" alt="多级联动菜单" /> </a></li>
<li><a href="http://www.cnblogs.com/cloudgamer/archive/2009/07/07/FixedTips.html"> <img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_song3.jpg" alt="浮动定位提示" /> </a></li>
<li><a href="http://www.cnblogs.com/cloudgamer/archive/2010/02/01/LazyLoad.html"> <img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_song4.jpg" alt="数据延迟加载" /> </a></li>
<li><a href="http://www.cnblogs.com/cloudgamer/archive/2009/12/01/Quick_Upload.html"> <img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_song5.jpg" alt="简便文件上传" /> </a></li>
</ul>
<ul class="num" id="idNum">
</ul></div>
    </div>
    </form>
    
<script>    var nums = [], timer, n = $$("idSlider2").getElementsByTagName("li").length,
st = new SlideTrans("idContainer2", "idSlider2", n, {
    onStart: function() {//设置按钮样式
        forEach(nums, function(o, i) { o.className = st.Index == i ? "on" : ""; })
    }
});
    for (var i = 1; i <= n; AddNum(i++)) { };
    function AddNum(i) {
        var num = $$("idNum").appendChild(document.createElement("li"));
        num.innerHTML = i--;
        num.onmouseover = function() 
        {
            timer = setTimeout(function() 
            {
                num.className = "on"; st.Auto = false; st.Run(i); 
            }, 200);
        }
        num.onmouseout = function() { clearTimeout(timer); num.className = ""; st.Auto = true; st.Run(); }
        nums[i] = num;
    }
    st.Run();
</script>
</body>
</html>/*****************************************************************//*****************运行正常的子页面 Login.aspx  *******************/
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head><title>JavaScript 图片滑动切换效果</title>
<script src="../App_Themes/DefaultPage/MainJS.JS" type="text/javascript"></script>
</head>
<body>
<style type="text/css"> </style><style type="text/css"> 
.container, .container img{width:280px; height:200px;}
.container img{border:0;vertical-align:top;}
.container ul, .container li{list-style:none;margin:0;padding:0;}
 
.num{ position:absolute; right:5px; bottom:5px; font:12px/1.5 tahoma, arial; height:18px;}
.num li{
float: left;
color: #d94b01;
text-align: center;
line-height: 16px;
width: 16px;
height: 16px;
font-family: Arial;
font-size: 11px;
cursor: pointer;
margin-left: 3px;
border: 1px solid #f47500;
background-color: #fcf2cf;
}
.num li.on{
line-height: 18px;
width: 18px;
height: 18px;
font-size: 14px;
margin-top:-2px;
background-color: #ff9415;
font-weight: bold;
color:#FFF;
}
</style>
仿淘宝/alibaba图片切换：<div class="container" id="idContainer2">
<ul id="idSlider2">
<li><a href="http://www.cnblogs.com/cloudgamer/archive/2009/12/22/ImagePreview.html"> <img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_song1.jpg" alt="图片上传预览" /> </a></li>
<li><a href="http://www.cnblogs.com/cloudgamer/archive/2009/08/10/FixedMenu.html"> <img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_song2.jpg" alt="多级联动菜单" /> </a></li>
<li><a href="http://www.cnblogs.com/cloudgamer/archive/2009/07/07/FixedTips.html"> <img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_song3.jpg" alt="浮动定位提示" /> </a></li>
<li><a href="http://www.cnblogs.com/cloudgamer/archive/2010/02/01/LazyLoad.html"> <img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_song4.jpg" alt="数据延迟加载" /> </a></li>
<li><a href="http://www.cnblogs.com/cloudgamer/archive/2009/12/01/Quick_Upload.html"> <img src="http://images.cnblogs.com/cnblogs_com/cloudgamer/143727/r_song5.jpg" alt="简便文件上传" /> </a></li>
</ul>
<ul class="num" id="idNum">
</ul></div>
<br /><script>    var nums = [], timer, n = $$("idSlider2").getElementsByTagName("li").length,
st = new SlideTrans("idContainer2", "idSlider2", n, {
    onStart: function() {//设置按钮样式
        forEach(nums, function(o, i) { o.className = st.Index == i ? "on" : ""; })
    }
});
    for (var i = 1; i <= n; AddNum(i++)) { };
    function AddNum(i) {
        var num = $$("idNum").appendChild(document.createElement("li"));
        num.innerHTML = i--;
        num.onmouseover = function() 
        {
            timer = setTimeout(function() 
            {
                num.className = "on"; st.Auto = false; st.Run(i); 
            }, 200);
        }
        num.onmouseout = function() { clearTimeout(timer); num.className = ""; st.Auto = true; st.Run(); }
        nums[i] = num;
    }
    st.Run();
</script>
 
<br /></body>
</html>/*****************************************************************/