Dim curTop As Integer
Dim stopAdd As Boolean
Private Sub Cmd_Click(Index As Integer)
    If Not stopAdd Then
        Load Cmd(Cmd.UBound + 1)
        Cmd(Cmd.UBound).Caption = Cmd.UBound
        If Cmd(Cmd.UBound - 1).Left + Cmd(Cmd.UBound).Width * 2 > Form1.Width Then
         curTop = Cmd(Cmd.UBound - 1).Top + Cmd(Cmd.UBound - 1).Height
         Cmd(Cmd.UBound).Left = Cmd(0).Left
         Cmd(Cmd.UBound).Top = curTop
        Else
        Cmd(Cmd.UBound).Top = curTop
        Cmd(Cmd.UBound).Left = Cmd(Cmd.UBound - 1).Left + Cmd(Cmd.UBound - 1).Width
        End If
        If curTop + Cmd(0).Height * 2 > Form1.Height Then  ' border limit
          stopAdd = True
        Else
        Cmd(Cmd.UBound).Visible = True
        End If
    End If
End Sub
Private Sub Form_Load()
  curTop = 120
End Sub