Gets the error number that describes the specific cause of the most recent general connection failure (when the last returned error has the value ErrConnectionError).
If no connection failure has occurred, this property returns zero. Use ConnectionErrorMessage to retrieve the error message. Use this property to retrieve information only when the last returned error equals ErrConnectionError. If you use ConnectionError for errors other than ErrConnectionError, you will be retrieving information that is not valid for the current error condition.