Private Sub TimSua_HoaDon_Click()
'On Error Resume Next '
Dim vtSheet As Integer, Chan As Byte, Le As Byte
vtSheet = CInt(TextBox_Cells.Text)
If vtSheet <= 11 Or vtSheet > 17 Then
MsgBox "Nhâp Sai Dong!", , "GPE.COM": Exit Sub
End If
If vtSheet Mod 2 = 0 Then Le = 1 Else Chan = 1...