C#

private void button1_Click(object sender, EventArgs e)
{
    frmNef frm1 = new frmNef();
    if (textBox1.Text == "maphanga" && textBox2.Text == "marsha" || textBox1.Text == "nkosi" && textBox2.Text == "mdu" || textBox1.Text == "carrim" && textBox2.Text == "allerece" || textBox1.Text == "raphela" && textBox2.Text == "rachel" || textBox1.Text == "mazibuko" && textBox2.Text == "zoliswa")
    {
        this.DialogResult = DialogResult.OK;
        //this.DialogResult = DialogResult.OK;
    }



    else MessageBox.Show("Invalid Username and or Password supplied");



}

private void frmNef_Load(object sender, EventArgs e)
{

    Login login = new Login();
    if (login.ShowDialog(this) == DialogResult.OK)
    {
        return;
    }
    else this.Close();
    login.Close();
    login.Dispose();