htaccess redirect to www.

I'm sure this has been posted a thousand times, but I couldnt find a definitive answer.

I want to use htaccess to redirect mydomain.com to www.mydomain.com

Is this what I should use?

RewriteEngine On
Options +FollowSymlinks
RewriteBase /
RewriteCond %{HTTP_HOST} ^mydomain\.com
RewriteRule ^(.*)$ http://www.mydomain.com/$1 [R=permanent]

Code (markup):

any help would be appreciated

 

I use the following:

 

Use the same, but lead it off with