Uploads the image of a specified index in buffer to the FTP server in a specified image format.
.FTPUpload(fTPServer, sImageIndex, fTPRemoteFile, [optionalAsyncSuccessFunc, optionalAsyncFailureFunc]);
fTPServer: specifies the FTP server.
sImageIndex: specifies the index of image in buffer. The index is 0-based.
fTPRemoteFile: specifies the file name, path included.
The following two parameters are optional. If either one exists or both exist, the method is asynchronous, otherwise it's synchronous.
optionalAsyncSuccessFunc: callback function triggered when the file is uploaded successfully.
optionalAsyncFailureFunc: callback function triggered when the file failed to be uploaded.
Only valid when used synchronously.
true indicates success.
false indicates failure.
Currently this method is only valid in Windows & Mac.
Dynamic Web TWAIN processes the image format according to the extension of