jQuery: Limit a textarea

gistfile1.js

jQuery(document).ready(function($) {
	/*
	*	<textarea id="custom_excerpt">Text</textarea>
	*	<p id="error"></p>
	*/
	$('#custom_excerpt').keyup(function() {
        // get the limit from the maxlength attribute
        var limit = 100;

        // get the current text inside the textarea
        var text = $(this).val();

        // count the number of characters in the text
        var chars = text.length;

        if (chars > limit) {
            // and if there are use substr to get the text before the limit
            $(this).css({
                'border': '1px solid red',
                'background': '#fee1e8'
            });
            $('p#error').html((text.length) + " letters written.");
        } else {
            $(this).css({
                'border': 'none',
                'background': '#fff'
            });
            $('p#error').html((limit - text.length) + " letters remaining.");

            if(chars < 1 ){
               $('p#error').html("No letters remaining.");
            }   
        }
	});
});