A very good way of testing a website is Selenium: http://seleniumhq.org/
The Groovy driven alternative is Tellurium which provides an easier entry but is not as good as Selenium for more complex Use Cases: http://code.google.com/p/aost/
Code driven (JUnit-like):
- Java Tests for Selenium
- Selenium will start to interact with your WebBrowser, as guided by the Tests.
- Bears strong resemblance to normal UNIT Tests
Browser-driven:
- Create a Selenium Test Suite by recording your clicks and website navigation in your browser.
- Replay in your browser