sLocalPath: Path of the local (PC) file to upload.
sHostPath: Path of the target host file [usually : library/file(member) ]
The return value depends on the synchronous property.
If the synchronous property was set to TRUE, the return value specifies the outcome of the upload: TRUE if the upload was
successful, FALSE otherwise.
If the synchronous property was set to FALSE, the return value specifies whether the upload request has been successfully
accepted or not.
The outcome of the file transfer itself will be notified to the client through the EndOfFileTransfer or the Error events.