private async void jThinButton1_Click(object sender, EventArgs e)
        {
            SqlDataReader sqlReader = null;
            SqlCommand command = new SqlCommand("SELECT * FROM [accounts] WHERE login = '" + textBox1.Text + "' AND password = '" + textBox2.Text + "'", sqlconnection);

            try
            {
                sqlReader = await command.ExecuteReaderAsync();

                bool loginSuccess = false;

                while (await sqlReader.ReadAsync())
                {
                    loginSuccess = true;

                    Account.SetAccountData(Convert.ToInt32(sqlReader["documentid"]),
                        Convert.ToString(sqlReader["name"]),
                        Convert.ToString(sqlReader["secondname"]),
                        Convert.ToString(sqlReader["fathername"]),
                        Convert.ToString(sqlReader["login"]),
                        Convert.ToString(sqlReader["password"]),
                        Convert.ToString(sqlReader["phone"]),
                        Convert.ToString(sqlReader["email"])
                    );

                    Account.SetAccepted(Convert.ToInt32(sqlReader["accepted"]));

                    break;
                }

                if (loginSuccess)
                {
                    // if account not accepted
                    if ( Account.GetAccepted() == 0 )
                    {
                        label4.Visible = true;
                        label4.Text = "Аккаунт не активований (зачекайте перевірки)";
                    }
                    else
                    {
                        Main MainForm = new Main();

                        label4.Visible = false;

                        //MessageBox.Show(Account.mail, Account.mail, MessageBoxButtons.OK, MessageBoxIcon.Error);

                        // load main form
                        MainForm.Show();
                        MainForm.label_UpdateAccount();

                        Hide();
                    }

                }
                else
                {
                    label4.Visible = true;
                    label4.Text = "Пароль або логін невірний";
                }
            }

            catch (Exception ex)
            {
                MessageBox.Show(ex.Message.ToString(), ex.Source.ToString(), MessageBoxButtons.OK, MessageBoxIcon.Error);
            }

            finally
            {
                if (sqlReader != null)
                    sqlReader.Close();
            }
        }