Write a program segment that asks a user to enter the username he or she wants and checks the length of the entry. The username can be between 1-15 characters, inclusive. Since the space you have...

Write a program segment that asks a user to enter the username he or she wants and checks the length of the entry. The username can be between 1-15 characters, inclusive. Since the space you have allowed for the username can only hold 15 characters, check to make sure the user’s entry is no longer than this.