Getting custom data for ItemTemplate within asp:Repeater

<asp:Repeater ID="Repeater1" runat="server" DataSourceID="NewsDataSource">
  <HeaderTemplate>
    <table style="border-collapse: collapse;" bgcolor="#ffffee" border="0" cellpadding="2">
      <tbody><tr><td>
  </HeaderTemplate>
  <ItemTemplate>
      <p class="Pbullets" dir="ltr">
      <img src="img/bullet<%# getBulletImage(Container.DataItem) %>.gif" border="0"> <a href="page.asp" class="bullets" /><%# Eval("Title") %></a></p>
  </ItemTemplate>
  <FooterTemplate>
      </td></tr></tbody>
    </table>
  </FooterTemplate>
</asp:Repeater>

protected string getBulletImage(object dataItem)
{
  DataRowView row = dataItem as DataRowView;
  switch( int.Parse(row["field"].ToString()) )
  {
  case 1:
    return "A";
  case 2:
    return "B";
  case 3:
    return "C";
  }
  return "";
}