public void initialize()
 {
     retailForm   = new Retail();
     physicalForm = new Physical();
     retailForm.SetFM(this);
     physicalForm.SetFM(this);
 }
        private void BTNRetail_Click(object sender, EventArgs e)
        {
            this.Visible = false;
            Retail r = new Retail();

            r.Visible = true;
        }