The sample exam system will not work without cookies.
If you are using Internet Explorer then:
Scroll down to the cookie section and select either 'prompt before accepting cookies' or preferable ' always accept cookies'
If you are using netscape then:
Click the 'accept all cookies' option
Click here to try again once you've turned cookies on.
If this doesn't fix the problem then please email me with what sort of browser you are using and I'll figure out why it's not working for you!