Airports

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Aerodrome
{
    public partial class AddAirportForm : Form
    {
        public Airport Airport { get; set; }
        public AddAirportForm()
        {
            InitializeComponent();
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            if (validateName() && validateCity() && validateShortName())
            {
                Airport = new Airport(tbCity.Text, tbName.Text, tbShortName.Text);
                DialogResult = DialogResult.OK;
            }
        }

        private void btnCancel_Click(object sender, EventArgs e)
        {
            DialogResult = DialogResult.Cancel;
        }

        private void tbCity_Validating(object sender, CancelEventArgs e)
        {
            validateCity();

        }

        private void tbName_Validating(object sender, CancelEventArgs e)
        {
            validateName();
        }

        private void tbShortName_Validating(object sender, CancelEventArgs e)
        {
            validateShortName();
        }

        private Boolean validateCity()
        {
            if (tbCity.Text == "")
            {
                errorProvider1.SetError(tbCity, "Градот не смее да биде празен");
                return false;
            }
            else
            {
                errorProvider1.Clear();
                return true;
            }
        }

        private Boolean validateName()
        {
            if (tbName.Text == "")
            {
                errorProvider2.SetError(tbName, "Името не смее да биде празно");
                return false;
            }
            else
            {
                errorProvider2.Clear();
                return true;
            }
        }

        private Boolean validateShortName()
        {
            if (tbShortName.Text.Length != 3 || tbShortName.Text.ToUpper() != tbShortName.Text)
            {
                errorProvider3.SetError(tbShortName, "Кратенката мора да биде 3 големи букви");
                return false;
            }
            else
            {
                errorProvider3.Clear();
                return true;
            }
        }
    }
}