title: Featured Image on Wordpress
body: <p>I have a little problem... when I want to show the featured image on my posts, the chosen size isn't working (the photo is shown in it's own size). And I want the featured Image to be shown in the same width as the post total width but I have no clue!</p>
  
  <p>This is the code I'm using in the PHP section</p>
  
  <pre><code>if ( function_exists( 'add_theme_support' ) ) add_theme_support( 'post-thumbnails' ); set_post_thumbnail_size(640, 205);
  </code></pre>
  
  <p>My question is... where do I have to put this code?</p>
  
  <pre><code>&lt;?php add_theme_support( 'post-thumbnails' );?&gt;
  </code></pre>
  
  <p>And what would be the css I have to use to show it in the same width as the post total width?
  Thanks</p>