Simulate the operations of an ATM machine. First, the customer is prompted to enter his personal identification number pin (for this case study, we test only if this pin is formed by 4 digits, otherwise a message like "Invalid PIN, try again..." will be displayed) and the user is re-prompted to enter the pin. The customer is given three chances to enter his pin. If he/she fails during the three trials you display a message like "Sorry you can't continue, contact your bank for assistance."

If the pin is correct (formed by 4 digits), then the system will ask the customer for the receipt (1 for YES and 2 for NO) and a menu will be displayed containing five possible options to choose from: Fast Cash, Deposit, Withdraw, Balance, and Get Card Back. 

Here is an explanation of each of the 5 options:

Get card back: Display the message "Goodbye!" and exit program.

Fast Cash: Let the customer choose the amount of cash from a menu similar to the following:

Press 1--> $20.00      $40.00 <--2

          3--> $80.00      $100.00 <--4

Withdraw: Prompt the user for the amount of money he/she would like to withdraw and make sure that he/she has enough money for that.

Deposit: Promt the customer for the amount of deposit.

Balance: Just display the amount of money the customer has.

Don't forget to print the receipt if the customer wants one.

Sample execution: (text in brackets represents the user entry)

Virtual Bank at West

WELCOME

Enter PIN: [245]

Invalid PIN, Re-enter PIN: [5487]

 -clear screen-

Receipt Y -> Yes     No <- N

Enter choice: [N]

-clear screen-

CHOOSE FROM THE FOLLOWING

1-> Fast Cash    Withdraw <-2

3-> Deposit    Check balance <-4

5-> Get card back

Enter your choice: [4]

-clear screen-

Your balance is: $125.32

1-> Another Transaction     Get Card Back <-2

Enter your choice: [1]

-clear screen-

CHOOSE FROM THE FOLLOWING

1-> Fast Cash     Withdraw <-2

3-> Deposit          Check Balance <-4

5-> Get card back

Enter your choice: [2]

-clear screen-

Enter amount (enter 0 to cancel): [300.00]

Sorry, not enough balance

Enter amount (enter 0 to cancel): [30.00]

Take your cash...

-clear screen-

Your balance is: $124.32

1-> Another transaction     Get card back <-2

Enter your choice: [1]

-clear screen-

CHOOSE FROM THE FOLLOWING

1-> Fast Cash     Withdraw <-2

3-> Deposit          Check Balance <-4

5-> Get card back

Enter your choice: [8]

Invalid entry

-clear screen-

CHOOSE FROM THE FOLLOWING

1-> Fast Cash     Withdraw <-2

3-> Deposit          Check Balance <-4

5-> Get card back

Enter your choice: [5]

-clear screen-