getResponseMessage
Returns the text message, if any, from the HTTP response.
General format
void getResponseMessage( msg )
Syntax rules
1. msg is an alphanumeric data item.
General rules
1. This method should be called after a request performed via one of the following methods: doGet, doPost, doPostEx or doPostMultipart.
1. Call this method to check if the request was successful. The response message value for success is "HTTP/1.0 200 OK".