def obtain_siblings(check = nil, orderby = 'post_title DESC')
      post = obtain_record(check)
      return nil if post.blank?
      p = post.siblings
      p = p.arrange(:order => orderby.to_sym) if !orderby.blank?
      filter_results(p)
    end
def obtain_siblings(check = nil, orderby = 'post_title DESC')
      post = obtain_record(check)
      return nil if post.blank?
      p = post.siblings
      p = p.arrange(:order => orderby.to_sym) if !orderby.blank?
      filter_results(p)
    end
returns the sibling records for the given post.
 Params:
 +check+:: ID, post_slug, or post_title - if this is nil it will use the @content variable (the current page)
 +depth+:: The nest depth that you want to children to return
 +orderby+:: What table column you want the posts to be ordered by