I tried to put additional custom name/value pair into the
HTTPService header. It looks like you can only add new parameters
if it is a POST. Is that true? I can't read all the content inside
the HTTPService header before I call the request.send(). Same for
the response header. Why Flex is hiding those information but
expose the attribute "header" for HTTPService? I am using Flex2, is
Flex3 making a difference in this sense?