beauty_saloon/AdminAuthForm.cs

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 BeautySaloon
{
    public partial class AdminAuthForm : Form
    {
        public AdminAuthForm()
        {
            InitializeComponent();
        }

        private void AuthButton_Click(object sender, EventArgs e)
        {
            if (AuthBox.Text == "0000")
            {
                AdminForm form = new AdminForm();
                form.Show();
                this.Close();
            }
            else
            {
                MessageBox.Show("Пароль введен неверно!");
                AuthForm form = new AuthForm();
                form.Show();
                this.Close();
            }
        }
    }
}