从各方面简化文件检查 
Simple file checking from anywhere
By Matthew Kent, mace@pacificcoast.net
To keep my applications running smoothly, I often need to check that certain files exist. So, I注释：ve written a simple routine to make sure they do. Here it is: 

Public Sub VerifyFile(FileName As String)
  注释：
  On Error Resume Next
  注释：Open a specified existing file
  Open FileName For Input As #1
  注释：Error handler generates error message with file and exits the routine
  If Err Then
    MsgBox ("The file " & FileName & " cannot be found.")
    Exit Sub
  End If
  Close #1
注释：
End Sub

Now add a button to your form and place the code below behind the "Click" event.

Private Sub cmdVerify_Click()
  注释：
  Call VerifyFile("MyFile.txt")
  注释：
End Sub