module Hpricot::Traverse

def xpath
  if elem? and has_attribute? 'id'
    "//#{self.name}[@id='#{get_attribute('id')}']"
  else
    sim, id = 0, 0, 0
    parent.children.each do |e|
      id = sim if e == self
      sim += 1 if e.pathname == self.pathname
    end if parent.children
    p = File.join(parent.xpath, self.pathname)
    p += "[#{id+1}]" if sim >= 2
    p
  end
end