Insert media to WordPress

gistfile1.php

   function insertAttachment($file_handler,$post_id,$setthumb='false') {

        // check to make sure its a successful upload
        //if ($_FILES[$file_handler]['error'] !== UPLOAD_ERR_OK) __return_false();

        require_once(ABSPATH . "wp-admin" . '/includes/image.php');
        require_once(ABSPATH . "wp-admin" . '/includes/file.php');
        require_once(ABSPATH . "wp-admin" . '/includes/media.php');

        $attach_id = media_handle_upload( $file_handler, $post_id, array(), array( 'test_form' => false, 'test_upload' => false ) );

      //  if ($setthumb) update_post_meta($post_id,'_thumbnail_id',$attach_id);
     
        return $attach_id;
    }