docs: function ajax_return(data, status, xhr) {
      // If the update was successfull
      if (data.ok) {
  	// Forget old value
  	this.removeData('old-value');
  	// Add a green V to the right
  	this.parent().next()
  	    .off('click')
  	    .html('V')
  	    .css('color', 'LimeGreen')
  	    .attr('title', 'Update OK');
  
  	// If we modified the id
  	if (this.attr('id') == 'id') {
  	    var url = '/user?id=' + encodeURIComponent(this.val());
  	    // update the link in the header...
  	    $('#user-link')
  		.text(this.val())
  		.attr('href', url);
  	    // ...and the url in the adress bar
  	    history.pushState(null, null, url);
  	}
      } else {
  	// Add a red X to the right
  	var elem = this;
  	elem.parent().next()
  	    .html('X')
  	    .css('color', 'red')
  	    .attr('title', data.message)
  	    .one('click', function() { 	  // if the X is clicked, restore original data
  		elem.val(elem.data('old-value'));
  		$(this)
  		    .empty()
  		    .removeAttr('title');
  	    });
      }
      // reactivate the control
      this.prop('disabled', false);
  }