Expected behaviour is described in the HTTP specification.
First, visit the test page. The results may vary. Typically what should happen is that some sort of user feedback should be given, explaining that a problem has occured.
Next, visit the result page. This will tell you what happened, and will reset the log in preparation for another run.
Note: do not simultaneously run this test from the same machine using the same web browser more than once, as the results are stored in a file that is specific to the IP address and user agent string that the request comes from.