input: def vowelCheck(inputString): 
      """Detect and return the first vowel in the given string.
      >>> vowelCheck('Hello World')
      'e'
      >>> vowelCheck('Python Programming')
      'o'
      """
      vowels = ['a','e','i','o','u','A','E','I','O','U'] 
      for x in inputString: 
          if x in vowels: 
              return x
output:     return None