private void btnLogin_Click(object sender, EventArgs e)
        {
            if (txtUserName.Text.Equals("Administrator") && txtPassword.Text.Equals("123"))
            {
                this.DialogResult = DialogResult.OK;
                //stockForm newStockForm = new stockForm();
                //newStockForm.DialogResult = DialogResult.OK;
 
                //newStockForm.Show();
                //newStockForm.RegisterMainForm(this);
                //this.Hide();
                //Application.Run(new stockForm());
                //this.Close();
            }
            else if (txtUserName.Text.Equals("Clerk") && txtPassword.Text.Equals("123"))
            {
                this.DialogResult = DialogResult.Yes;
                //billForm newBillForm = new billForm();
                //newBillForm.DialogResult = DialogResult.Yes;
                //newBillForm.Show();
                //newBillForm.RegisterMainFormBill(this);
                //this.Hide();
            }
            else
            {
                MessageBox.Show("Please Enter correct details", "Login Error");
            }
        }

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