Why isn't my if not open working

[dpaton05]

I have a spreadsheet that checks if a file is open and the command works fine. I copied the command from the working spreadsheet to another spreadsheet and now I get the error sub or function not defined. isFileOpen is highlighted. Can someone help me see what I have missed please?

Sub LateCancel()

        Dim ws As Worksheet, sh As Worksheet, sht As Worksheet, wb As Workbook, WbPath As String, QTPath As String
        Set sh = Sheets("Totals")
        'Set sht = Sheets("Cancellations")
        Dim LCReq As String: LCReq = sh.[B32].Value
        Dim LCDt As String: LCDt = sh.[B34].Value
        WbPath = ThisWorkbook.Path
        QTPath = Left(WbPath, InStrRev(WbPath, "\") - 2)

Application.ScreenUpdating = False
       
        If Not isFileOpen("CSS_quoting_tool_29.5.xlsm") Then Workbooks.Open _
            QTPath & "\" & "CSS_quoting_tool_29.5.xlsm"
   
        For Each ws In Worksheets
                If ws.Name <> "Cancellations" And ws.Name <> "Totals" Then
                        With ws.[A3].CurrentRegion
                                .AutoFilter 1, LCDt
                                .AutoFilter 3, LCReq
                                .Offset(1).EntireRow.Copy sh.Range("A" & Rows.Count).End(xlUp).Offset(1)
                                .Offset(1).EntireRow.Delete
                                .AutoFilter
                        End With
                End If
        Next ws
       
sh.Range("B32,B34").ClearContents
Application.ScreenUpdating = True

End Sub

 

[Michael M]

Is this code in another WORKBOOK ?
If so, did you copy the IsFileOpen function as well ??

 

[dpaton05]

yes and yes

 

[Michael M]

Did you paste the function in a Standard Module ??

 

[dpaton05]

I just remembered that I forgot to paste the IsFileOpen function into that workbook. I did so and now I am not getting that error.

Thanks Michael.

 

[Michael M]

I did ask that question !!...