$(function(){    
  $('a.site_required_action').click(function() {
    var self = jQuery(this);
    jQuery.post(self.attr("rel"), {
      "_method": "put",
      "authenticity_token": form_authenticity_token
    }, updateLabel, "json");
    return false;
  });
  
  function updateLabel(json) {
    a = "a.site_required_action[rel="+json.rel+"]";
    jQuery(a).html(json.label)
  }
});