On facebook Like button event, enable form.fb-like-form input elements

gistfile1.js

  // Setup a variable to contain all the form input elements to enable
  var myDisabledFields = "input, textarea, select, button";

  // The FB.Event.subscribe method lets us run some javascript on certain events. The "Like" event for the Javascript SDK is "edge.create"
  FB.Event.subscribe('edge.create',
    // Once we're subscribed, anytime the Like button is cliked Facebook sends us back some data in an array. 
    // We'll call that data array "response". 

      function(response) {
        // If you uncomment the next line, you'll see the data returned in your console
        // console.log(response); 

        // Let's use some jQuery to target form with the class "fb-like-form" and find and enable 
        // each of the matching input elements we put in our variable above    
        jQuery(".fb-like-form").find(myDisabledFields).each(function() {
          // Remove the "disabled" attribute for this element
          jQuery(this).removeAttr("disabled");
          
          // Optionally, do other stuff here.  

        });
      }
  );
   
  // Let's re-enable the form when someone "UnLikes" a Like button
  FB.Event.subscribe("edge.remove", function(response){
    jQuery(".fb-like-form").find(myDisabledFields).each(function() {
      jQuery(this).attr("disabled", "disabled");
    });
  });

Place the code above after your FORM and Facebook Like Button markup and before the closing BODY tag.