Tugas Looping

Code Pemrogramannya :

Private Sub Command1_Click()
List1.Clear
For a = 1 To Val(Text1.Text) - 1
kal = " "
For b = 1 To a
kal = kal & Str(b)
Next b
List1.AddItem kal
Next
For c = Text1.Text To 1 Step -1
kal = " "
For d = 1 To c
kal = kal & Str(d)
Next d
List1.AddItem kal
Next

End Sub