(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);