列表框中的蓝色(被选中状态)上下移动?该如何解决

列表框中的蓝色(被选中状态)上下移动??
定义列表框中的条数为x.

command1为向上移动:x-1

command2为向下移动:x+1

初始值为列表框中的最后一记录。


请写出代码来,谢谢!

------解决方案--------------------
VB code

Option Explicit
Dim x As Integer
Private Sub Command1_Click()
    x = x + 1
    If x > List1.ListCount Then
       x = List1.ListCount
       Exit Sub
    End If
    List1.Selected(List1.ListCount - x) = True
End Sub

Private Sub Command2_Click()
    x = x - 1
    If x < 1 Then x = 1: Exit Sub
    List1.Selected(List1.ListCount - x) = True

End Sub

Private Sub Form_Load()
   Dim i As Integer
   For i = 0 To 10
       List1.AddItem i
   Next
   List1.Selected(List1.ListCount - 1) = True
   x = 1
End Sub