首页图片显示不出来

下面是我的代码
<%@ Page Language="C#" MasterPageFile="~/Common/MasterPage.master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" Title="Untitled Page"%><%@ Register Src="Common/NetProduct.ascx" TagName="NetProduct" TagPrefix="uc1" %>
<%@ Register Src="Common/JavaProduct.ascx" TagName="JavaProduct" TagPrefix="uc2" %>
<%@ Register Src="Common/ASPProduct.ascx" TagName="ASPProduct" TagPrefix="uc3" %>
<%@ Register Src="Common/VCProduct.ascx" TagName="VCProduct" TagPrefix="uc4" %>
<%@ Register Src="Common/VBProduct.ascx" TagName="VBProduct" TagPrefix="uc5" %>
<%@ Register Src="Common/DelphiProduct.ascx" TagName="DelphiProduct" TagPrefix="uc6" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
   <table width="505" border="0" cellpadding="0" cellspacing="0">
          <tr>
            <td style="height:30; background-image:url(../images/chanpin.gif);" >&nbsp;</td>
          </tr>
          <tr>
            <td valign="top" style="height:30; background-image:url(../images/chanpin2.gif);"><table width="505" style="height:659" border="0" cellpadding="0" cellspacing="0">
              <tr>
                <td style="height:418; width:232;" valign="top"><uc1:NetProduct ID="NetProduct1" runat="server" />
                  <uc3:ASPProduct ID="ASPProduct1" runat="server" /></td>
                <td style="width:273;" valign="top"><uc2:JavaProduct ID="JavaProduct1" runat="server" />
                  <uc4:VCProduct ID="VCProduct1" runat="server" /></td>
              </tr>
              <tr>
                <td style="height:221;" valign="top"><uc5:VBProduct ID="VBProduct1" runat="server" />
                  </td>
                <td valign="top"><uc6:DelphiProduct ID="DelphiProduct1" runat="server" />
                  </td>
              </tr>
            </table></td>
          </tr>
          <tr>
            <td  style="height:30; background-image:url(../images/dibuzhong.gif);" valign="top" ></td>
          </tr>
        </table> 
</asp:Content>
这是首页，图片显示不出来，连模板页MasterPage.master里的图片都显示不出来，但是其他页面都没有问题图片可以显示