vb题目 急急急！！！！！！

'求500以内最大的10个能被13或17整除的自然数之和 Private Sub Form_Click() Dim a(1 To 10), i, j As Integer For i = 1 To 500 If (i Mod 13 = 0) Or (i Mod 17 = 0) Then a(1) = a(2): a(2) = a(3): a(3) = a(4): a(4) = a(5): a(5) = a(6): a(6) = a(7): a(7) = a(8): a(8) = a(9):