to read unknown input

Hi How do I go about printing or echoing unknown input. I submit variables from my script to a URL which processes them and returns variables to me. Now besides them using ASP, I have no idea what the variables are that they sent back to me since the variable names they supplied does not work. All I want to do is now print out the variable names with their values. I read the bit about fopen (php://stdin), but how would I then print out everything that is in stdin. Thanks in advance Regards Ernst Bekker