爸爸们！！VB小题不会做

Option Explicit
Const MAXSIZE = 10
Dim d(MAXSIZE + 1) As Integer, n As Integer



Private Sub Command1_Click()
    Dim i As Integer, j As Integer
    n = Val(txtSize.Text)
     
    If n <= 0 Or n > MAXSIZE Then
        txtSize = "数据个数必须大于0！"
        Exit Sub
    End If
      
    Randomize
    lstUnsorted.Clear
   
    For i = 1 To n
        j = Int(11 * Rnd)+20
        lstUnsorted.AddItem Str$(j)
        d(i) = j
    Next

    Command2.Enabled = True

End Sub



Private Sub Command2_Click()    '冒泡
    Dim i, j, TEMP, NextElement
    lstSorted.Clear
    For i = 1 To n - 1
        For j = n To i Step -1
            If d(j) < d(j - 1) Then
                TEMP = d(j)
                d(j) = d(j - 1)
                d(j - 1) = TEMP
            End If
        Next
    Next
    For i = 1 To n
        lstSorted.AddItem d(i)
    Next
End Sub