Inet & Error Trapping

I use an Inet control to upload a file :

With InetTr
.Execute , "PUT ..."
While .StillExecuting
DoEvents
Wend
.Execute , "CLOSE"
End With

This works well but I need some help to know what the best way is to be ABSOLUTELY SURE the file has been correctly uploaded to the distant server.

Right now I experiment with the StateChanged event but I can't bring this to work !
The states rised at each execution seem to be different from one time to another ...

Please help me understand this concept.
Thanks a lot

Try a simple CRC check... you'll know if what you sent is the same as what was received.

Please, can you tell me what is CRC check meens??