Gracias por su ayuda, hice el cambio pero me sale un error de compilación después del cambio.
Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.
Compiler Error Message: BC30456: 'DropDownList1_SelectedIndexChanged' is not a member of 'ASP.tipopropuesta_aspx'.
Source Error:
Line 45: <strong><span style="font-size: 10pt">Grupo</span></strong></td>
Line 46: <td style="width: 100px; height: 15px">
Line 47: <asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataGrupo" AppendDataBoundItems="true" EnableViewState="false" DataTextField="Descripcion"
Line 48: DataValueField="IdGrupo" Style="position: relative" OnSelectedIndexChanged="DropDownList1_SelectedInde xChanged">
Line 49: <asp:ListItem Selected="True" Value="0">:: Seleccione ::</asp:ListItem>
Source File: C:\Documents and Settings\Edgar Salcedo\Mis documentos\Visual Studio 2005\WebSites\SIP\TipoPropuesta.aspx Line: 47