input: Write a function to take two matrices, A and B, and produce a new matrix C where each element in C is the product of the corresponding elements from A and B. If the matrices A and B have different dimensions, return an error message. If either matrix is empty, return an error message.
  assert elementwiseMultiply([[3, 4], [1, 2]], [[7, 5], [0, 1]])==[[21, 20], [0, 2]]
  assert elementwiseMultiply([[1, 2], [3, 4]], [[5, 6], [7, 8]])==[[5, 12], [21, 32]]
  assert elementwiseMultiply([], [[1, 2]])=="Error: Matrix A is empty"
  assert elementwiseMultiply([[1, 2]], [])=="Error: Matrix B is empty"
  assert elementwiseMultiply([[1, 2]], [[1], [2]])=="Error: Matrices have different dimensions"
output: def elementwiseMultiply(A, B):
      if not A:
          return "Error: Matrix A is empty"
      if not B:
          return "Error: Matrix B is empty"
      if len(A) != len(B) or len(A[0]) != len(B[0]):
          return "Error: Matrices have different dimensions"
      C = [[A[i][j] * B[i][j] for j in range(len(A[0]))] for i in range(len(A))]
      return C