#functions go here

def yes_no(question):

    """checks user responce to a question is yes / no (y/n), returns 'yes' or 'no' """

    while True:

        response = input(question).lower()

        # check the user says yes / no/y/n
        if response == "yes" or response == "y":
            return "yes"
        elif response == "no" or response == "n":
            return "no"
        else:
            print("please answer yes or no ")

def instructions():
    """prints instructions"""

    print("***instructions***")





#main routine

#ask the user if they want instructions (check they say yes / no
want_instructions = yes_no("Do you want to see the instructions? ")

# Display the instructions if the user wants to see them...
if want_instructions == "yes":
    intructions()

print()
print("program continues")