(function($) {
    $.fn.extend({
        limit: function(limit, element) {
            var interval, f;
            var self = $(this);
            $(this).focus(function() {
                interval = window.setInterval(substring, 100)
            });
            $(this).blur(function() {
                clearInterval(interval);
                substring()
            });
            substringFunction = "function substring(){ var val = $(self).val();var length = val.length;if(length > limit){$(self).val($(self).val().substring(0,limit));}";
            if (typeof element != 'undefined') substringFunction += "if($(element).html() != limit-length){$(element).html((limit-length<=0)?'0':limit-length);}";
            substringFunction += "}";
            eval(substringFunction);
            substring()
        }
    })
})(jQuery);