Redirect non-www to www using .htaccess

Hi all!

I've a doubt: I'm trying that when everyone type vidaelectronica.com (which is my wp) would be redirected to www.vidaelectronica.com

I've done this with this code:

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

By the way, i'm also trying that ALL adresses without www would be redirected to a www adress, but i don't know how to do it. I'm meaning to this:
vidaelectronica.com/forum/x/xx-x-x-x-xxx.html to http://www.vidaelectronica.com/forum...x-x-x-xxx.html

How can I do that? Thanks!