Mod Rewrite / htaccess Help

Hi Guys,

I am trying to make it so that my blog can be found at domain.com/blog/ and then the posts are domain.com/blog/blog-title/

I have used the below code but it doesn't seem to work:

RewriteRule ^blog/([a-z_0-9-]*)/([a-z_0-9-]*)$ blogpost.php?first=$1&second=$2 [L]
RewriteRule blog blog.php

Code (markup):

Thanks

 

From what i've heard...most mod-rewrite is used for SEO?