I do what elgoog does, but the code in my .htaccess file looks a little different. Here’s what I use:
RewriteEngine On
RewriteCond %{HTTP_HOST} ^5starslots.com$ [NC]
RewriteRule ^(.*)$ http://www.5starslots.com/$1 [R=301,L]
Whenever someone goes to a non-www page of your site, the above code (in the .htaccess file) instantly redirects the page to the www version.
Try going to http://5starslots.com/new-slots-1.html and you can see how this works. The non-www is redirected to the www version immediately.