Detect if user hits cancel from user input type box

I have the following code which gets all the files in a director. The problem is if a user hits cancel then it exits the subroutine but my subsequent code does not know that cancel was hit.

Any ideas on how to identify if cancel was hit...........

'***********************************************************************
'***********************************************************************
'     Procedure obtained from LeithRoss at "Excel Forum"
'     http://www.excelforum.com/excel-programming/776444-reading-in-the-
'     files-in-a-directory-into-an-array-directory-chosen-by-user.html
'
'***********************************************************************
'***********************************************************************
Sub get_list_of_files_and_path(file_array() As Variant, Path1 As String)

Dim Cnt As Long
Dim ExcelFiles() As Variant
Dim FilePath As String
Dim FileName As String
Dim objShell As Object
    
    Set objShell = CreateObject("Shell.Application")
    
    Set oFolder = objShell.BrowseForFolder(0, "Pick a Folder to Open", 0)
    If oFolder Is Nothing Then Exit Sub
    
      FilePath = oFolder.Self.Path & "\"
      
      'MsgBox (FilePath)
      Path1 = FilePath
      
      'FileName = Dir(FilePath & "*.xls")
        FileName = Dir(FilePath & "*.*")

      If FileName = "" Then
         MsgBox "No Excel Files were Found in this Folder.", vbCritical
         Exit Sub
      End If
      

      Cnt = 1
        Do While FileName <> ""
          ReDim Preserve ExcelFiles(Cnt)
          ReDim Preserve file_array(Cnt)
          ExcelFiles(Cnt) = FilePath & FileName
          file_array(Cnt) = FileName
          'MsgBox (FileName)
          Cnt = Cnt + 1
          FileName = Dir()
        Loop
    
    

End Sub