private void Button3_Click(object sender, EventArgs e)
        {
            this.Hide();
            regestration mark = new regestration();

            mark.Show();
        }
 private void Submit_Click(object sender, EventArgs e)
 {
     if (SecurityText.Text == "cabalan1973")
     {
         MessageBox.Show("Success!!!");
         this.Hide();
         regestration mark = new regestration();
         mark.Show();
     }
     else
     {
         MessageBox.Show("Invalid Code!!");
         SecurityText.Text = "";
     }
 }