Can you post some of your code? If you use the POST method, $ENV{QUERY_STRING} won't have any data. However, if you are using the CGI.pm module or something similar, you won't even have to worry about that. As for why your content type is getting displayed in the browser, it's tough to say. Again, posting some code will help. I have a link below to my CGI course. You might find that helpful.