validasi status_aktif

Private Sub BtnAdd_Click(sender As Object, e As EventArgs) Handles BtnAdd.Click
        Try
            If Txttahun.Text = "" And Cmbsemester.Text = "" And Lblid.Text = "" And BtnAdd.Text = "Save" Then
                MsgBox("Data belum lengkap")
                Exit Sub
                '======================================================================
            ElseIf Txttahun.Text <> "" And Cmbsemester.Text <> "" And Lblid.Text <> "" And cmbstatus.Text <> "" And BtnAdd.Text = "Save" Then
                conn.Open()
                sstr = "SELECT * FROM v_tbltahun "
                cmd = New MySqlCommand(sstr, conn)
                dr = cmd.ExecuteReader
                dr.Read()
                conn.Close()
                If dr.HasRows Then
                    Lblid.Text = dr.Item("id_tahun") 'Primary key
                Else
                    Lblid.Text = "" 'jika lblid.text<>"" diexsekusi oleh query update
                End If
                MsgBox("tahun " & Txttahun.Text & ", semester " & Cmbsemester.Text & " sudah ada")
                Refresh_data()
                Exit Sub
                '======================================================================
            ElseIf Txttahun.Text <> "" And Cmbsemester.Text <> "" And Lblid.Text = "" And cmbstatus.Text <> "" And BtnAdd.Text = "Save" Then
                conn.Open()
                sstr = "call sp_Insert_tblTahun(null,@p1,@p2,@p3)"
                cmd = New MySqlCommand(sstr, conn)
                cmd.Parameters.Add("@p1", MySqlDbType.String, 10).Value = Txttahun.Text
                cmd.Parameters.Add("@p2", MySqlDbType.Enum, 7).Value = Cmbsemester.Text
                cmd.Parameters.Add("@p3", MySqlDbType.Enum, 1).Value = cmbstatus.Text
                cmd.ExecuteNonQuery()
                conn.Close()
                MsgBox("Data berhasil disimpan")
                Refresh_data()
                Exit Sub

                '======================================================================
            ElseIf Txttahun.Text <> "" And Cmbsemester.Text <> "" And Lblid.Text <> "" And cmbstatus.Text <> "" And BtnAdd.Text = "Update" Then
                conn.Open()
                sstr = "Call sp_update_tbltahun(@p1,@p2,@p3,@p4)"
                cmd = New MySqlCommand(sstr, conn)
                cmd.Parameters.Add("@p1", MySqlDbType.VarChar, 11).Value = Lblid.Text
                cmd.Parameters.Add("@p2", MySqlDbType.VarChar, 10).Value = Txttahun.Text
                cmd.Parameters.Add("@p3", MySqlDbType.Enum, 7).Value = Cmbsemester.Text
                cmd.Parameters.Add("@p4", MySqlDbType.Enum, 1).Value = cmbstatus.Text
                cmd.ExecuteNonQuery()
                conn.Close()
                MsgBox("Data berhasil di Update")
                Refresh_data()
            End If
        Catch ex As Exception
            MsgBox(ex.ToString)
        Finally
            conn.Dispose()
        End Try
    End Sub
Private Sub Cmbsemester_SelectedValueChanged(sender As Object, e As EventArgs) Handles Cmbsemester.SelectedValueChanged
        Try
            If BtnAdd.Text = "Save" Then
                conn.Open()
                sstr = "SELECT id_tahun from v_tbltahun where nama_tahun='" & Txttahun.Text & "' And semester='" & Cmbsemester.Text & "'"
                cmd = New MySqlCommand(sstr, conn)
                dr = cmd.ExecuteReader
                dr.Read()

                If dr.HasRows Then
                    Lblid.Text = dr.Item("id_tahun")
                Else
                    Lblid.Text = ""
                End If
                conn.Close()
            ElseIf BtnAdd.Text = "Update" Then
                conn.Open()
                sstr = "SELECT id_tahun from v_tbltahun where nama_tahun='" & Txttahun.Text & "' And semester='" & Cmbsemester.Text & "'"
                cmd = New MySqlCommand(sstr, conn)
                dr = cmd.ExecuteReader
                dr.Read()

                If dr.HasRows Then
                    Lblid.Text = dr.Item("id_tahun")
                End If
                conn.Close()
            End If

        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try
    End Sub