/* 
 * Useful jQuery extension by P.Simpson
 */
(function($) {
  $.fn.isBlank = function() {
    return this.val().replace(/^\s\s*/, '').replace(/\s\s*$/, '').length == 0;
  };
  $.fn.visible = function() {
    return this.each(function() {
	  return $(this).css("visibility", "visible");
	});
  };
  $.fn.hidden = function() {
    return this.each(function() {
	  return $(this).css("visibility", "hidden");
	});
  };
})(jQuery);