add rel="prettyPhoto" to images in the content

add-rel-prettyphoto-to-images-in-content

//start function to add rel attribute to image links
function rel_prettyPhoto($link) {
       global $post;
       $find ="/<a(.*?)href=('|")(.*?).(bmp|gif|jpeg|jpg|png)('|")(.*?)>/i";
       $replace = '<a$1href=$2$3.$4$5 rel="prettyPhoto['. $post->ID .']" $6>';
       $link = preg_replace($find, $replace, $link);
       return $link;
} //end function to add rel attribute to image links

//add rel attribute function to the content filter
add_filter('the_content', 'rel_prettyPhoto');
//add rel attribute function to the attachment link filter
add_filter('wp_get_attachment_link', 'rel_prettyPhoto');