# Do the following to create a program that simulates how websites ensure that 
# everyone has a unique username.
# Make a list of five or more usernames called current_users. Make another 
# list of five usernames called new_users. Make sure one or two of the new 
# usernames are also in the current_users list.
# Loop through the new_users list to see if each new username has already been 
# used. If it has, print a message that the person will need to enter a new 
# username. If a username has not been used, print a message saying that the 
# username is available.
# Make sure your comparison is case insensitive. If 'John' has been used, 
# 'JOHN' should not be accepted.
current_users = ['eric', 'willie', 'admin', 'erin', 'Ever']
new_users = ['sarah', 'Willie', 'PHIL', 'ever', 'Iona']

current_users_lower = [user.lower() for user in current_users]

# Note: If you’re not comfortable with list comprehensions yet, the list 
# current_users_lower can be generated using a loop:
# current_users_lower = []
#for user in current_users:
#    current_users_lower.append(user.lower())

for new_user in new_users:
    if new_user.lower() in current_users_lower:
        print(f"Sorry {new_user}, that name is taken.")
    else:
        print(f"Great, {new_user} is still available.")
