This may be kind of a dumb question, but the script for the facebook button on the like button page is different from the script on the javascript sdk page, but similar. Did facebook just forget to update the documentation or do I need both scripts?

The like button page gives:

<div id="fb-root"></div>
<script> (function(d, s, id) {
  var js, fjs = d.getElementsByTagName(s)[0];
  if (d.getElementById(id)) return;
  js = d.createElement(s); js.id = id;
  js.src = "//connect.facebook.net/en_US/all.js#xfbml=1";
  fjs.parentNode.insertBefore(js, fjs);
  }(document, 'script', 'facebook-jssdk'));</script>

But on the javascript sdk page:

<div id="fb-root"></div>
<script>
  window.fbAsyncInit = function() {
  FB.init({
  appId      : 'YOUR_APP_ID', // App ID
  channelUrl : '//WWW.YOUR_DOMAIN.COM/channel.html', // Channel File
  status     : true, // check login status
  cookie     : true, // enable cookies to allow the server to access the session
  xfbml      : true  // parse XFBML
});

// Additional initialization code here
};

// Load the SDK Asynchronously
(function(d){
 var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
 if (d.getElementById(id)) {return;}
 js = d.createElement('script'); js.id = id; js.async = true;
 js.src = "//connect.facebook.net/en_US/all.js";
 ref.parentNode.insertBefore(js, ref);
  }(document));
</script>