Getting Username when workbook is opened Readonly

Sub TestVBA()
'// Just change the file to test here
Const strFileToOpen As String = "Cata.xls"
If IsFileOpen(strFileToOpen) Then
MsgBox strFileToOpen & " is already Open" & _
vbCrLf & "By " & LastUser(strFileToOpen), vbInformation, "File in Use"
Else
MsgBox strFileToOpen & " is not open", vbInformation
End If
End Sub
Function IsFileOpen(strFullPathFileName As String) As Boolean
Dim hdlFile As Long


On Error GoTo FileIsOpen:
hdlFile = FreeFile
Open strFullPathFileName For Random Access Read Write Lock Read Write As hdlFile
IsFileOpen = False
Close hdlFile
Exit Function
FileIsOpen:
'// Someone has it open!
IsFileOpen = True
Close hdlFile
End Function
Private Function LastUser(strPath As String) As String
Dim strXl As String
Dim strFlag1 As String, strflag2 As String
Dim i As Integer, j As Integer
Dim hdlFile As Long
Dim lNameLen As Byte


strFlag1 = Chr(0) & Chr(0)
strflag2 = Chr(32) & Chr(32)
hdlFile = FreeFile
Open strPath For Binary As #hdlFile
strXl = Space(LOF(hdlFile))
Get 1, , strXl
Close #hdlFile
j = InStr(1, strXl, strflag2)
#If Not VBA6 Then
'// Xl97
For i = j - 1 To 1 Step -1
If Mid(strXl, i, 1) = Chr(0) Then Exit For
Next
i = i + 1
#Else
'// Xl2000+
i = InStrRev(strXl, strFlag1, j) + Len(strFlag1)
#End If
'// IFM
lNameLen = Asc(Mid(strXl, i - 3, 1))
LastUser = Mid(strXl, i, lNameLen)
End Function

Public Function WhoHasFileOpen(strFileName As String) As String


   '// strFileName is a fully qualified path, filename & extension...
   Dim strTempFile As String
   Dim iPos As Integer
   Dim objFSO As Object
   
   iPos = InStrRev(strFileName, "\")
   
   strTempFile = Left(strFileName, iPos - 1) & "\~$" & Mid(strFileName, iPos + 1)
   
   Set objFSO = CreateObject("Scripting.FileSystemObject")


   If objFSO.FileExists(strTempFile) Then
      WhoHasFileOpen = GetFileOwner(strTempFile)
   Else
      WhoHasFileOpen = vbNullString
   End If
   
   Set objFSO = Nothing


End Function


Private Function GetFileOwner(strFileName) As String


   Dim objWMIService As Object
   Dim objFileSecuritySettings As Object
   Dim objSD As Object
   Dim iRetVal As Integer
   
   Set objWMIService = GetObject("winmgmts:")
   Set objFileSecuritySettings = _
   objWMIService.Get("Win32_LogicalFileSecuritySetting='" & strFileName & "'")
   iRetVal = objFileSecuritySettings.GetSecurityDescriptor(objSD)


   If iRetVal = 0 Then
      GetFileOwner = objSD.Owner.Name
   Else
      GetFileOwner = "Unknown"
   End If


   Set objWMIService = Nothing
   Set objFileSecuritySettings = Nothing
   Set objSD = Nothing


End Function

Public Function WhoHasFileOpen(strFileName As String) As String
     
     '// strFileName is a fully qualified path, filename & extension...
    Dim objFSO As Object
     
    Set objFSO = CreateObject("Scripting.FileSystemObject")
     
    If objFSO.FileExists(strFileName) Then
        WhoHasFileOpen = GetFileOwner(strFileName)
    Else
        WhoHasFileOpen = vbNullString
    End If
     
    Set objFSO = Nothing
     
End Function