private void BtnAdd_Click(object sender, RoutedEventArgs e)
        {
            string id        = TBId.Text.Trim();
            string serie1Str = TBSerie1.Text.Trim();
            string serie2Str = TBSerie2.Text.Trim();
            string serie3Str = TBSerie3.Text.Trim();
            string serie4Str = TBSerie4.Text.Trim();

            if (id.Equals("") || serie1Str.Equals("") || serie2Str.Equals("") || serie3Str.Equals("") || serie4Str.Equals(""))
            {
                MessageBox.Show("You must fill all the fields.", "Attention !", MessageBoxButton.OK, MessageBoxImage.Warning);
            }
            else
            {
                if (!_shootersModel.Exists <Shooter>("Id", id))
                {
                    MessageBox.Show("This shooter id does not exist.", "Attention !", MessageBoxButton.OK, MessageBoxImage.Warning);
                }
                else
                {
                    if (_resultsModel.Exists <Result>("ShootedById", id))
                    {
                        MessageBox.Show("This shooter already have results for this competition.", "Attention !", MessageBoxButton.OK, MessageBoxImage.Warning);
                    }
                    else
                    {
                        if (float.TryParse(serie1Str, out float serie1) && float.TryParse(serie2Str, out float serie2) && float.TryParse(serie3Str, out float serie3) && float.TryParse(serie4Str, out float serie4))
                        {
                            Result newResult = new Result(serie1, serie2, serie3, serie4, id);
                            if (newResult.IsSavable())
                            {
                                try {
                                    _resultsModel.Add <Result>(newResult);
                                    _results.Add(newResult);
                                    MessageBox.Show("The shooter's results have been added.", "Results added !", MessageBoxButton.OK, MessageBoxImage.Information);
                                    Close();
                                } catch (Exception ex) {
                                    MessageBox.Show(ex.Message, "Attention !", MessageBoxButton.OK, MessageBoxImage.Warning);
                                }
                            }
                            else
                            {
                                SortedDictionary <string, string> errors = newResult.GetInvalidFields();
                                MessageBox.Show(errors.Values.First(), "Attention !", MessageBoxButton.OK, MessageBoxImage.Warning);
                            }
                        }
                        else
                        {
                            MessageBox.Show("All series should be int or float (sep = ,)", "Attention !", MessageBoxButton.OK, MessageBoxImage.Warning);
                        }
                    }
                }
            }
        }