#functions go here

def yes_no(question):

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

    while True:

        response = input(question).lower()

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

# Main routine


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

    print("""
    **** Instructions ****

Roll the dice and try to win!
    """)


# 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":
    instructions()

print()
print("program continues")