Cancels the currently in-progress fax operation.
Public Sub CancelFax()
This function is asynchronous, and will return before the faxing operation is cancelled. This is due to the fact that canceling a fax can take up to several seconds. Your application should rely on the CompletionStatus notification event to determine when the fax device actually completes processing.
If there is no faxing operation in progress, then this method will just return without doing anything.