Checking whether an RSS feed is read by or visited in the browser

[Vin0rz]

Hey, I got an RSS feed which is generated by PHP. Now, I'd like the contents of the feed to be displayed when the user just visits the URL in the browser. To do this however, I need to be able to differentiate between the page being read as an RSS feed or as being displayed in the browser. Any ideas on how to do this?

Thanks in advance.