Troubleshooting code for export to text file.

I was wondering if someone would be willing to help me troubleshoot this code. I got the code from here: http://www.cpearson.com/excel/ImpText.aspx

I'm sure that it works fine. But I was trying to modify it to fit my needs. I can step through it fine, but it doesn't generate the text file for the cells I'm selecting. At least, I think I'm selecting them. I might have goofed up the cell ranges.

I want to select 15 rows in a single column. So each cell will go on it's own line in a text file, and I don't want any character separation. In the macro that calls the function(ExportToTextFile), I changed

Sep:=";",

to this

Sep:="",

So here's the full code that I'm trying to debug. I have a separate macro that calls this function:

Function ExportToTextFile(FName As String, _
        Sep As String, SelectionOnly As Boolean, _
        AppendData As Boolean)

        Dim WholeLine As String
        Dim FNum As Integer
        Dim RowNdx As Long
        Dim ColNdx As Integer
        Dim StartRow As Long
        Dim EndRow As Long
        Dim StartCol As Integer
        Dim EndCol As Integer
        Dim CellValue As String

        'Range(Cells(2, 1), Cells(17, 1)).Copy
        Application.ScreenUpdating = False
        On Error GoTo EndMacro:
        FNum = FreeFile


        If SelectionOnly = True Then
        With Selection
        StartRow = .Cells(8).Row
        StartCol = .Cells(5).Column
        EndRow = .Cells(23).Row
        EndCol = .Cells(5).Column
        End With
        End If

        If AppendData = True Then
        Open FName For Append Access Write As #FNum
        End If

        For RowNdx = StartRow To EndRow
        WholeLine = ""
        For ColNdx = StartCol To EndCol
        If Cells(RowNdx, ColNdx).Value = "" Then
            CellValue = Chr(34) & Chr(34)
        Else
           CellValue = Cells(RowNdx, ColNdx).Text
        End If
        WholeLine = WholeLine & CellValue & Sep
        Next ColNdx
        WholeLine = Left(WholeLine, Len(WholeLine) - Len(Sep))
        Print #FNum, WholeLine
        Next RowNdx

EndMacro:
        On Error GoTo 0
        Application.ScreenUpdating = True
        Close #FNum

End Function

It appears that nothing happens when I get to this line of

Open FName For Append Access Write As #FNum

If anyone can take the time to explain to me what I'm doing wrong, I would really appreciate it.

Thanks,
-gshock