textarea 超过字数

<textarea name="" id="FashionStatement" cols="30" rows="10"></textarea>
<div id="statementRowChk"></div>

$('#FashionStatement').val(''); 
var limitNum = 40; 
var pattern = '还可以输入' + limitNum + '字'; 
$('#statementRowChk').html(pattern); 
$('#FashionStatement').keyup( 
function() { 
var remain = $(this).val().length; 
if (remain > 40) { 
pattern = '字数超过限制，请适当删除部分内容'; 
} 
else { 
var result = limitNum - remain; 
pattern = '还可以输入' + result + '字'; 
} 
$('#statementRowChk').html(pattern); 
} 
);