private void Modify_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                Dog dog = (Dog)this.DogsGrid.SelectedItem;

                if (dog != null)
                {
                    Window modifyDog = new AddSpecimenWindow(dog.DogId);
                    modifyDog.Left = this.Left;
                    modifyDog.Top  = this.Top;
                    modifyDog.Show();

                    this.Close();
                }
                else
                {
                    System.Windows.MessageBox.Show("Nie wybrano psa.", "Błąd", System.Windows.MessageBoxButton.OK);
                }
            }
            catch (Exception x)
            {
                ShowError(x.Message);
            }
        }
        private void AddSpecimen_Click(object sender, RoutedEventArgs e)
        {
            Window addSpecimenWindow = new AddSpecimenWindow();

            addSpecimenWindow.Left = this.Left;
            addSpecimenWindow.Top  = this.Top;
            addSpecimenWindow.Show();
            this.Close();
        }