private void BindGrid()
        {
            DataSet ds = cRegistro.obtenerGuiaEntrada(objConexion);

            GuiaList.DataSource = ds;
            GuiaList.DataBind();
            cRegistro.closeConexion();
        }
 protected void listaTipoGuia_SelectedIndexChanged(object sender, EventArgs e)
 {
     if (listaTipoGuia.SelectedValue.Equals("1"))
     {
         DataSet ds = cRegistro.obtenerGuiaEntrada(objConexion);
         GuiaList.DataSource = ds;
         GuiaList.DataBind();
         cRegistro.closeConexion();
     }
     else
     {
         DataSet ds = cRegistro.obtenerGuiaSalida(objConexion);
         GuiaList.DataSource = ds;
         GuiaList.DataBind();
         cRegistro.closeConexion();
     }
 }