VB6.0中如何把Listbox的表项，上移或下移一个位置

Question

有两个button1，button2，
点button1向上移动一个，
点button2，向下移动一个
谁能实现，代码要简洁，我追加50分

Answer 1

'上移
Private Sub Command1_Click()
Dim n As Long
Dim s As String

If List1.ListIndex > 0 Then
n = List1.ListIndex
s = List1.List(n)
List1.RemoveItem List1.ListIndex
List1.AddItem s, n - 1
End If

End Sub

'下移
Private Sub Command2_Click()
Dim n As Long
Dim s As String

If List1.ListIndex <> -1 And List1.ListIndex < List1.ListCount - 1 Then
n = List1.ListIndex
s = List1.List(n)
List1.RemoveItem List1.ListIndex
List1.AddItem s, n + 1
End If

End Sub