While userName is less than four characters long, display error message to user, and prompt for new username entry. Read in new value from user, and store it in userName. Otherwise, proceed.

While userName is less than four characters long, display error message to user, and prompt for new username entry. Otherwise, proceed.

Display error message to user, and prompt for new username entry. If userName is less than four characters long, loop back to the error message. Otherwise, proceed.

Display error message to user, and prompt for new username entry. Read in new value from user, and store it in userName. If userName is less than four characters long, loop back to the error message. Otherwise, proceed.