input: Write a function to detect a vowel in a given string and return the first detected vowel.
  
  def vowelCheck(inputString): 
      vowels = ['a','e','i','o','u','A','E','I','O','U'] 
      for x in inputString: 
          if x in vowels: 
              return x
  
  assert vowelCheck("Hello World")=="e"
  assert vowelCheck("Python Programming")=="o"
  assert vowelCheck("Coding") is None
  assert vowelCheck("AEIOUaeiou")=="A"
output: def vowelCheck(inputString): 
      vowels = ['a','e','i','o','u','A','E','I','O','U'] 
      for x in inputString: 
          if x in vowels: 
              return x