Create a .htaccess file with the below code, it will ensure that all requests coming in to domain.com will get redirected to www.domain.com The .htaccess file needs to be placed in the root directory of your old website (i.e the same directory where your index file is placed)
Ah, that was easy enough. Found this little one for others who don't know how do make this file. http://www.apluskb.com/scripts/How_do_I_create_an_answer2168.html