请教关于Spacegallery一个问题，谢谢

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="picture.aspx.cs" Inherits="picture" %><!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>Spacegallery</title>
    <link rel="stylesheet" media="screen" type="text/css" href="css/layout.css" />
    <link rel="stylesheet" media="screen" type="text/css" href="css/spacegallery.css" />
    <link rel="stylesheet" media="screen" type="text/css" href="css/custom.css" />
    <script type="text/javascript" src="js/jquery.js"></script>
    <script type="text/javascript" src="js/eye.js"></script>
    <script type="text/javascript" src="js/utils.js"></script>
    <script type="text/javascript" src="js/spacegallery.js"></script>
    <script type="text/javascript" src="js/layout.js"></script>
    
    <script type="text/javascript">
        function ShowDiv()
        {
            var SDiv=document.getElementById("DDiv");
            
            SDiv.style.display="block";
            
            var str=['D:/picture/1.jpg','D:/picture/2.jpg','D:/picture/3.jpg','D:/picture/4.jpg'];
             
            //var oDiv=document.getElementsByTagName("img"); 
             
            //for(var i=0;i<str.length;i++) 
            //{ 
            //    oDiv[i].setAttribute("src",str[i]);                
            //}           
            
            var oEle=document.createElement("img");
            oEle.setAttribute("src",str[0]);
            var PDiv=document.getElementById("myGallery");
            PDiv.appendChild(oEle);
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
     <div id="DDiv" class="wrapper" style="display:none;">
        <div id="myGallery" class="spacegallery" style="width:800px; height:600px;">
    <!--<img id="img2" src="images/bw3.jpg" alt="" />
    <img id="img3" src="images/bw3.jpg" alt="" />-->
</div>
    </div>
    <input type="button" id="SDiv" value="显示图片" onclick="ShowDiv()" />
    </form>
</body>
</html>为什么这样不好用啊？是不是层myGallery里必须有<img id="img3" src="images/bw3.jpg" alt="" />这个才行啊，我想动态加载怎么处理？