2 diffrent PRs

I agree that this is the best method, But what i feel is that u shd stop using http://sitename.com

 

If you use Google sitemap you can choose your preferred domain.

 

how do you do that?

I've used google sitemaps for the last year.

 

this is interesting. i would do this.

 

This link show you how, What's a preferred domain?

 

Using Google sitemap to make www.yourdomain.com is useul only for Google.What bout other search engines? Using htaccess is the best solution.

The above code redirect all request to non www pages to the homepage. It should be

RewriteEngine On
RewriteCond %{HTTP_HOST} ^thewebmasterstool.com
RewriteRule (.*) http://www.thewebmasterstool.com\1 [R=301,L]

Code (markup):

A more general solution will be

RewriteEngine on
RewriteCond %{HTTP_HOST} !^www [NC]
RewriteRule (.*) http://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,NC,L]

Code (markup):

This works for subdomains too.