Session_1/Sseessiioonn1/Form1.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 Sseessiioonn1
{
    public partial class Main_Form : Form
    {
        public Main_Form()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string username = Textbox_login.Text;
            string password = Textbox_password.Text;

            if (INUserAuthenticated(username, password))
            {
                MessageBox.Show("Авторизация прошла успешно");
                Glavnoya_form frm = new Glavnoya_form();
                frm.Show();
                this.Hide();
            }
            else
            {
                MessageBox.Show("Ошибка авторизации!");
            }
        }

        private bool INUserAuthenticated(string username, string password)
        {
            if (username == "admin" && password == "admin")
            {
                return true;
            }
            else
            {
                return false;
            }


        }
    }
}