Trouble reading POST data that is not associated with a value.

Hi. I'm currently developing a system that accepts http requests containing xml data. A third-party application delivers the xml data in the post part of the http request. The post data is however not associated with any name. So it cannot be indexed as normal with $_POST["key"]. I've tried all kind of variations to write the post data to screen but it always reports "", null or Array. The count of the $_POST array is 0. However the $_SERVER["CONTENT_LENGTH"] is between 300 and 400 bytes. The data is there, but how can i access it? The person that can help me solve this really saves my day. (And next two weeks. :) Best regards Marcus