Find out how the message gets displayed, and then check for that condition. It would help us to help you better if you told us a bit more about the circumstances and what you're trying to do, but I assume that you're doing Q&A testing of a web application and are trying to automate that.

To find what data gets sent over the wire, use Wireshark or the mozilla live http headers. Then use your Perl code to make the same requests to retrieve the application status.