input: Write a function to search for an element in a list and return its index.
  assert searchElement([3, 10, 7, 12], 7) == 2
  assert searchElement([3, 10, 7, 12], 10) == 1
  assert searchElement([3, 10, 7, 12], 5) == -1
output: def searchElement(lst, element):
      try:
          return lst.index(element)
      except ValueError:
          return -1