fb：与当前页面不同。

<fb:like>

<iframe>

<fb:like href=\"http://URL\" send=\"false\" layout=\"button_count\" width=\"85\" show_faces=\"false\" font=\"\"></fb:like>

  (function() {
    var e = document.createElement(\'script\'); e.async = true;
    e.src = document.location.protocol +
      \'//connect.facebook.net/en_US/all.js\';
    document.getElementById(\'fb-root\').appendChild(e);
  }());

  window.fbAsyncInit = function() {
    FB.init({appId: \'XXXXX\',
            status: true,
            cookie: true,
            xfbml: true});
  });