code for opening a file

Isn't this code supposed to open a file? It's not working. There is no error but it doesn't open file but then debugs on line input.

Sub DemoWhileClause()
    ' Page 87 Middle
    Open "C:\Users\amartino\Desktop\invoice.txt" For Input As #1
    r = 1
    Do While Not EOF(1)
        Line Input #FileNumber, Data
        If Not Left(Data, 5) = "TOTAL" Then
            ' Import this row
            r = r + 1
            Cells(r, 1).Value = Data
        End If
    Loop
    Close #1
End Sub

#FileNumber is not defined in your code. Try Line Input #1, Data