Your comments

Weird. I don't see what you described. I tried to upload an MS-Word file with the same file. It simply overwrite without asking. I tried again with a JPG file. Same thing.

You said it would warn and cancel the upload process. Not in my case. ???

I tried out your codes and it worked perfectly. But since you said updates would wipe out the file, I will keep-in-view this.

I must be blind. Thanks.