XML Flash ActionScript

package{
  import flash.display.Sprite;
  
  public class Main extends Sprite{
    public function Main(){
        var novel:XML = 
            ActionScript                    
            J, J
            Books Ltd  
          ;
        
        var author:XML = novel.AUTHOR[0];
        // Previous sibling
        trace(author.parent().*[author.childIndex(  )-1]);  
        // Next sibling
        trace(author.parent().*[author.childIndex(  )+1]);  
    }
  }
}