private void cargarCurso()
 {
     try
     {
         CboCurso.DataSource    = NSeleccionar.Seleccionar();
         CboCurso.ValueMember   = "Id";
         CboCurso.DisplayMember = "Curso";
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message + ex.StackTrace);
     }
 }
 private void cargarSeccion()
 {
     try
     {
         CboSeccion.DataSource    = NSeleccionar.SeleccionarSeccion(Convert.ToInt32(CboCurso.SelectedValue));
         CboSeccion.ValueMember   = "Id";
         CboSeccion.DisplayMember = "Nombre";
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message + ex.StackTrace);
     }
 }