when i add the below code from the extended starter kits the content of the default.aspx duplicated and the content page

become not in parellel with master so the layout not adjustable

the code is exact from microsoft site which is :

<div id="content">
   <asp:DataList ID="DataList1" runat="server" 
    DataSourceID="SqlDataSource1">
      <ItemTemplate>
         <h3>Welcome   to My Site</h3>
         <p><%# Eval("Homepage_Welcome")%></p>
         <hr   />
         <div id="whatsnew">
            <h4>What's New</h4>
            <p><%# Eval("Homepage_WhatsNew") %></p>
         </div>
         <div id="coollinks">
            <h4>Cool Links</h4>
            <ul class="link">
            <li><a HREF="http://forums.asp.net/AddPost.aspx?ForumID=1003#" TARGET="_self">Lorem ipsum dolositionr</a></li>
            <li><a HREF="http://forums.asp.net/AddPost.aspx?ForumID=1003#" TARGET="_self">Lorem ipsum dolositionr</a></li>
            <li><a HREF="http://forums.asp.net/AddPost.aspx?ForumID=1003#" TARGET="_self">Lorem ipsum dolositionr</a></li>
            <li><a HREF="http://forums.asp.net/AddPost.aspx?ForumID=1003#" TARGET="_self">Lorem ipsum dolositionr</a></li>
            <li><a HREF="http://forums.asp.net/AddPost.aspx?ForumID=1003#" TARGET="_self">Lorem ipsum dolositionr</a></li>
            </ul>
         </div>
         <hr />
         <h4>What's Up Lately </h4>
         <p><%# Eval("Homepage_WhatsUpLately") %></p>
      </ItemTemplate>
   </asp:DataList>
</div>

pls help me solve this puzzle