c# program for cash withdraw and cash deposit using oop

/*
 * C# Program to Display the ATM Transaction
 */
using System;
class program
{
    public static void Main()
    {
 
        int amount = 1000, deposit, withdraw;
        int choice, pin = 0, x = 0;
        Console.WriteLine("Enter Your Pin Number ");
        pin = int.Parse(Console.ReadLine());
        while (true)
        {
            Console.WriteLine("********Welcome to ATM Service**************\n");
            Console.WriteLine("1. Check Balance\n");
            Console.WriteLine("2. Withdraw Cash\n");
            Console.WriteLine("3. Deposit Cash\n");
            Console.WriteLine("4. Quit\n");
            Console.WriteLine("*********************************************\n\n");
            Console.WriteLine("Enter your choice: ");
            choice = int.Parse(Console.ReadLine());
            switch (choice)
            {
            case 1:
                Console.WriteLine("\n YOUR BALANCE IN Rs : {0} ", amount);
                break;
            case 2:
                Console.WriteLine("\n ENTER THE AMOUNT TO WITHDRAW: ");
                withdraw = int.Parse(Console.ReadLine());
                if (withdraw % 100 != 0)
                {
                  Console.WriteLine("\n PLEASE ENTER THE AMOUNT IN MULTIPLES OF 100");
                }
                else if (withdraw > (amount - 500))
                {
                   Console.WriteLine("\n INSUFFICENT BALANCE");
                }
                else
                {
                   amount = amount - withdraw;
                   Console.WriteLine("\n\n PLEASE COLLECT CASH");
                   Console.WriteLine("\n YOUR CURRENT BALANCE IS {0}", amount);
                }
                break;
            case 3:
                Console.WriteLine("\n ENTER THE AMOUNT TO DEPOSIT");
                deposit = int.Parse(Console.ReadLine());
                amount = amount + deposit;
                Console.WriteLine("YOUR BALANCE IS {0}", amount);
                break;
            case 4:
                Console.WriteLine("\n THANK U USING ATM");
            break;
            }
        }
        Console.WriteLine("\n\n THANKS FOR USING OUT ATM SERVICE");
    }
 }