unexpected mistake

   mistakesMade=0
   availableLetters=abcdefghijklmnopqrstuvwxyz
   lettersGuessed=''
   letter=''
   letter1=''
   print('Welcome to the game, Hangman!')
   print('I am thinking of a word that is '+ len(secretWord) + ' letters long.')

   while mistakesMade < 8:
       print('You have '+ 8-mistakesMade + ' guesses left.')
       print('Available letters: ' + getAvailableLetters(lettersGuessed)
       letter1 = raw_input('Please guess a letter: ')
       letter=letter1.lowercase()
       if letter in lettersGuessed:
           print("Oops! You've already guessed that letter: "+ getGuessedWord(secretWord, lettersGuessed))
       elif  letter in secretWord:
           print('Good guess '+ getGuessedWord(secretWord, lettersGuessed))
       else:
           print('Oops! That letter is not in my word: '+ getGuessedWord(secretWord, lettersGuessed))
           mistakesMade+=1
       lettersGuessed+=letter
       if isWordGuessed(secretWord, lettersGuessed):
           return print('Congratulations, you won!')
   print('Sorry, you ran out of guesses. The word was '+ secretWord +'.')