adRotator 显示不出图片不知道为什么

Advertisment.xml<Advertisment>
  <ad>
    <ImageUrl>Image/Autumn Leaves.jpg</ImageUrl>
    <NavigateUrl>aaaaaaaa</NavigateUrl>
    <AlternateText>aaaaaaaaa</AlternateText>
    <Keyword>bbbbbbbb</Keyword>
    <Impression>80</Impression>
  </ad>
  <ad>
    <ImageUrl>Image/Creek.jpg</ImageUrl>
    <NavigateUrl>aaaaaaaa</NavigateUrl>
    <AlternateText>aaaaaaaaa</AlternateText>
    <Keyword>bbbbbbbb</Keyword>
    <Impression>80</Impression>
  </ad>
 
  
</Advertisment>
Default.aspx  <asp:AdRotator ID="AdRotator1" runat="server" DataSourceID="XmlDataSource1" />
        <asp:XmlDataSource ID="XmlDataSource1" runat="server" 
            DataFile="~/Advertisment.xml"></asp:XmlDataSource>也尝试过：
Default.aspx
<asp:AdRotator ID="AdRotator1" runat="server" AdvertisementFile="~/Advertisment.xml" />
            DataFile="~/Advertisment.xml"></asp:XmlDataSource>都不行？？？