private void btn_edit_Click(object sender, EventArgs e)
 {
     if (string.IsNullOrEmpty(txt_filterName.Text) == false | string.IsNullOrEmpty(txt_filterSurname.Text) == false | string.IsNullOrEmpty(txt_filterYear.Text) == false)
     {
         btn_addOrEdit.Text = "Apply Changes";
         int             id_pick      = (int)lst_users.SelectedValue;
         Name_to_listbox selectedName = personas.Single(c => c.Id == id_pick);
         txt_name.Text          = selectedName.Name;
         txt_surname.Text       = selectedName.Surname;
         txt_year.Text          = selectedName.BirthYear.ToString();
         txt_place.Text         = selectedName.BirthPlace;
         txt_filterName.Text    = "";
         txt_filterSurname.Text = "";
         txt_filterYear.Text    = "";
     }
     else
     {
         btn_addOrEdit.Text = "Apply Changes";
         int             id_pick      = (int)lst_users.SelectedValue;
         Name_to_listbox selectedName = personas.Single(c => c.Id == id_pick);
         txt_name.Text    = selectedName.Name;
         txt_surname.Text = selectedName.Surname;
         txt_year.Text    = selectedName.BirthYear.ToString();
         txt_place.Text   = selectedName.BirthPlace;
     }
 }
        private void btn_addOrEdit_Click(object sender, EventArgs e)
        {
            //add part
            if (btn_addOrEdit.Text == "Add User")
            {
                Name_to_listbox myNameBox = new Name_to_listbox();
                myNameBox.Id         = id_val;
                myNameBox.Name       = txt_name.Text;
                myNameBox.Surname    = txt_surname.Text;
                myNameBox.BirthYear  = int.Parse(txt_year.Text);
                myNameBox.BirthPlace = txt_place.Text;

                personas.Add(myNameBox);

                //BindPersonsToListBox();
                ResetForm();
            }

            // Edit part
            else
            {
                if (string.IsNullOrEmpty(txt_filterName.Text) == false | string.IsNullOrEmpty(txt_filterSurname.Text) == false | string.IsNullOrEmpty(txt_filterYear.Text) == false)
                {
                    int             id_pick      = (int)lst_users.SelectedValue;
                    Name_to_listbox selectedName = filteredBlist.Single(c => c.Id == id_pick);

                    Name_to_listbox myNameBox = new Name_to_listbox();
                    myNameBox.Id         = id_val;
                    myNameBox.Name       = txt_name.Text;
                    myNameBox.Surname    = txt_surname.Text;
                    myNameBox.BirthYear  = int.Parse(txt_year.Text);
                    myNameBox.BirthPlace = txt_place.Text;

                    filteredBlist[id_pick] = myNameBox;

                    //BindPersonsToListBox();
                    ResetForm();
                }
                else
                {
                    int             id_pick      = (int)lst_users.SelectedValue;
                    Name_to_listbox selectedName = personas.Single(c => c.Id == id_pick);

                    Name_to_listbox myNameBox = new Name_to_listbox();
                    myNameBox.Id         = id_val;
                    myNameBox.Name       = txt_name.Text;
                    myNameBox.Surname    = txt_surname.Text;
                    myNameBox.BirthYear  = int.Parse(txt_year.Text);
                    myNameBox.BirthPlace = txt_place.Text;

                    personas[id_pick] = myNameBox;

                    //BindPersonsToListBox();
                    ResetForm();
                }
            }
        }
 private void btn_showDetails_Click(object sender, EventArgs e)
 {
     if (string.IsNullOrEmpty(txt_filterName.Text) == false | string.IsNullOrEmpty(txt_filterSurname.Text) == false | string.IsNullOrEmpty(txt_filterYear.Text) == false)
     {
         int             id_pick      = (int)lst_users.SelectedValue;
         Name_to_listbox selectedName = personas.Single(c => c.Id == id_pick);
         lbl_details.Text = selectedName.Name.ToString() + " " + selectedName.Surname.ToString() +
                            " was born in " + selectedName.BirthPlace.ToString() + " " + "in " + selectedName.BirthYear.ToString();
     }
     else
     {
         int             id_pick      = (int)lst_users.SelectedValue;
         Name_to_listbox selectedName = personas.Single(c => c.Id == id_pick);
         lbl_details.Text = selectedName.Name.ToString() + " " + selectedName.Surname.ToString() +
                            " was born in " + selectedName.BirthPlace.ToString() + " " + "in " + selectedName.BirthYear.ToString();
     }
 }
 private void btn_delete_Click(object sender, EventArgs e)
 {
     if (string.IsNullOrEmpty(txt_filterName.Text) == false | string.IsNullOrEmpty(txt_filterSurname.Text) == false | string.IsNullOrEmpty(txt_filterYear.Text) == false)
     {
         int             id_pick      = (int)lst_users.SelectedValue;
         Name_to_listbox selectedName = personas.Single(c => c.Id == id_pick);
         personas.Remove(selectedName);
         txt_filterName.Text    = "";
         txt_filterSurname.Text = "";
         txt_filterYear.Text    = "";
     }
     else
     {
         int             id_pick      = (int)lst_users.SelectedValue;
         Name_to_listbox selectedName = personas.Single(c => c.Id == id_pick);
         personas.Remove(selectedName);
     }
 }