Session1_02/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 AMONIC_Airlines02
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void pictureBox1_Click(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            {
                var Login1 = "j.doe@amonic.com";
                var Pass1 = "123";
                var Login2 = "k.omar@amonic.com";
                var Pass2 = "4258";
                var Login3 = "h.saeed@amonic.com";
                var Pass3 = "2020";
                var Login4 = "a.hobart@amonic.com";
                var Pass4 = "6996";
                var Login5 = "k.anderson@amonic.com";
                var Pass5 = "4570";
                var Login6 = "h.wyrick@amonic.com";
                var Pass6 = "1199";
                var Login7 = "marie.horn@amonic.com";
                var Pass7 = "55555";
                var Login8 = "m.osteen@amonic.com";
                var Pass8 = "9800";


                if ((t_login.Text == Login1) && (t_Parol.Text == Pass1))
                {
                    Form2 form2 = new Form2();
                    form2.Show();
                    this.Hide();
                }
                if ((t_login.Text == Login2) && (t_Parol.Text == Pass2))
                {
                    Form2 form2 = new Form2();
                    form2.Show();
                    this.Hide();
                }
                if ((t_login.Text == Login3) && (t_Parol.Text == Pass3))
                {
                    Form2 form2 = new Form2();
                    form2.Show();
                    this.Hide();
                }
                if ((t_login.Text == Login4) && (t_Parol.Text == Pass4))
                {
                    Form2 form2 = new Form2();
                    form2.Show();
                    this.Hide();
                }
                if ((t_login.Text == Login5) && (t_Parol.Text == Pass5))
                {
                    Form2 form2 = new Form2();
                    form2.Show();
                    this.Hide();
                }
                if ((t_login.Text == Login6) && (t_Parol.Text == Pass6))
                {
                    Form2 form2 = new Form2();
                    form2.Show();
                    this.Hide();
                }
                if ((t_login.Text == Login7) && (t_Parol.Text == Pass7))
                {
                    Form2 form2 = new Form2();
                    form2.Show();
                    this.Hide();
                }
                if ((t_login.Text == Login8) && (t_Parol.Text == Pass8))
                {
                    Form2 form2 = new Form2();
                    form2.Show();
                    this.Hide();
                }
                if ((t_login.Text != Login3) && (t_Parol.Text != Pass3) &&
                    (t_login.Text != Login1) && (t_Parol.Text != Pass1) &&
                    (t_login.Text != Login2) && (t_Parol.Text != Pass2) &&
                    (t_login.Text != Login4) && (t_Parol.Text != Pass4) &&
                    (t_login.Text != Login5) && (t_Parol.Text != Pass5) &&
                    (t_login.Text != Login6) && (t_Parol.Text != Pass6) &&
                    (t_login.Text != Login7) && (t_Parol.Text != Pass7) &&
                    (t_login.Text != Login8) && (t_Parol.Text != Pass8))
                {
                    MessageBox.Show("Неверный логин или пароль");
                }
            }
        }
        private void button2_Click(object sender, EventArgs e)
        {
            MessageBoxButtons msb = MessageBoxButtons.YesNo;
            String message = "Вы действительно хотите выйти?";
            String caption = "Выход";
            if (MessageBox.Show(message, caption, msb) == DialogResult.Yes)
                this.Close();
        }
    }
}