(function($){
     $.fn.extend({
         limit: function(element) {

			var interval;
			var self = $(this);
                        var limit = self.attr('rel');

			$(this).focus(function(){
				interval = window.setInterval(substring,100);
			});

			$(this).blur(function(){
				clearInterval(interval);
				substring();
			});

			function substring(){
				var length = self.val().length;
				if(element)
					$(element).children("span").html( (limit-length<=0)?'0':limit-length);
				if(length > limit)
					self.val( $(self).val().substring(0,limit) );
			}

			substring();

        }
    });
})(jQuery);