Bài kiểm tra Visual Basic nè ( ĐỀ 1)

Private Sub cmdChon_Click()
If lst1.ListIndex = -1 Then Exit Sub
lst2.AddItem lst1.List(lst1.ListIndex)
lst1.RemoveItem lst1.ListIndex
End Sub
Private Sub cmdChontat_Click()
Dim i
For i = o To lst1.ListCount - 1
lst2.AddItem lst1.List(i)
Next i
lst1.Clear
End Sub

Private Sub cmdChuyen_Click()
Dim i
For i = 0 To lst2.ListCount - 1
lst1.AddItem lst2.List(i)
Next i
lst2.Clear
End Sub

Private Sub cmdNap_Click()
Dim filename, filenumber, anItem
filename = "G:\New Folder\Desktop\Bai kiem tra\Danhsach.txt"
filenumber = FreeFile
anItem = ""
Open filename For Input As filenumber
Do While Not EOF(filenumber)
Line Input #filenumber, anItem
lst1.AddItem anItem
Loop
End Sub

Private Sub cmdXoa_Click()
If lst1.ListIndex = -1 Then Exit Sub
lst1.RemoveItem lst1.ListIndex
End Sub

Private Sub Command1_Click()
End
End Sub