Title pictures

Hi,

I just upgraded to Atout theme, which is great!
I have a question.. every time i go inside the post I see at the headline the picture even if it appear in the text itself. im kind of new to wordpress and in the past in one of the posts someone told me to add the following to function.php page. I did it again here but it doesnt work. any suggestion?

global $wpdb;
$wpdb->query( “
DELETE FROM $wpdb->postmeta
WHERE meta_key = ‘_thumbnail_id’
” );