initial setup issues with Apache2

i have an issue with the LAMP server i set up under Ubuntu 9.10.

I followed the beginners guide on how to setup apache in Ubuntu, but the problem is that the site is only accessable when i drop the www. prefix. ie i can view the site on mealies.co.uk

When i type www.mealies.co.uk i just get the template apache It Works! page.

How can i get the www.mealies.co.uk url to view the site?

Thanks

Andrew