Payment Form

Payment Form

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Billing
{
    public partial class frm_PrintBill : Form
    {
        public double balance=0,billamount=0,cashtendered=0;
        public frm_PrintBill()
        {
            InitializeComponent();
        }

        private void btn_Cancel_Click(object sender, EventArgs e)
        {
            this.DialogResult = System.Windows.Forms.DialogResult.Cancel;
            this.Close();
        }

        private void txt_CashTendered_KeyUp(object sender, KeyEventArgs e)
        {
            if(e.KeyCode==Keys.Enter)
            {
                if (txt_CashTendered.TextLength > 0)
                {
                    billamount = Convert.ToDouble(txt_Amount.Text);
                    cashtendered = Convert.ToDouble(txt_CashTendered.Text);
                    balance = cashtendered - billamount;
                    

                    txt_CashTendered.Text = string.Format("{0:0.00}", cashtendered);
                    txt_Balance.Text = string.Format("{0:0.00}", balance);
                    this.SelectNextControl(txt_CashTendered, true, true, true, true);
                }
                else
                {
                    return;
                }
               
            }
        }

        private void btn_Print_Click(object sender, EventArgs e)
        {
            if (txt_CashTendered.TextLength <= 0)
            {
                return;
            }
            else
            {
                this.DialogResult = System.Windows.Forms.DialogResult.OK;
            }
        }
    }
}