В матрице поменять местами чётные и нечётные строки

Sub matrix()
Dim A(1 To 100, 1 To 100) As Integer
Dim I As Integer, J As Integer
Dim Sum As Integer
N = 0
J = 1
Do While Worksheets("Лист1").Cells(1, J).Value <> ""
  N = N + 1
  J = J + 1
Loop
For I = 1 To N
  For J = 1 To N
    A(I, J) = Worksheets("Лист1").Cells(I, J).Value
  Next J
 Next I
  
 For I = 1 To N
    If (I Mod 2 <> 0) And (I + 1 <= N) Then
     For J = 1 To N
        b = A(I, J)
        A(I, J) = A(I + 1, J)
        A(I + 1, J) = b
        Worksheets("Лист1").Cells(I, J).Value = A(I, J)
        Worksheets("Лист1").Cells(I + 1, J).Value = A(I + 1, J)
     Next J
    End If
Next I
 
End Sub

Private Sub CommandButton1_Click()
 
Dim A()
Dim I As Integer, J As Integer, N As Integer
N = 0
J = 1
Do While Worksheets("Лист1").Cells(1, J).Value <> ""
  N = N + 1
  J = J + 1
Loop
If N = 0 Then
MsgBox "ошибка"
Exit Sub
End If
ReDim A(N, N)
For I = 1 To N
  For J = 1 To N
    A(I, J) = Worksheets("Лист1").Cells(I, J).Value
  Next J
 Next I
  
 For I = 1 To N - 1 Step 2
 
     For J = 1 To N
        b = A(I, J)
        A(I, J) = A(I + 1, J)
        A(I + 1, J) = b
        Worksheets("Лист1").Cells(I, J).Value = A(I, J)
        Worksheets("Лист1").Cells(I + 1, J).Value = A(I + 1, J)
     Next J
   
Next I
 
 
End Sub