js统计textrea文本框中字数的代码

计算是字符长度
<TEXTAREA class=textarea id=text1 style="WIDTH: 220px; HEIGHT: 200px" cols=100  onchange="gbcount(this,document.getElementById('used'));" onkeyup="gbcount(this,document.getElementById('used'));">
</TEXTAREA>
已用字数：
<INPUT disabled maxLength=4 name=used size=5 value=0>
<script type="text/javascript">
function gbcount(message,used)
{
var lenE = message.value.length;
var lenC = 0;
var CJK = message.value.match(/[^x00-xff]/g);
var enter = message.value.match(/rn/g);
if (CJK != null) lenC += CJK.length;
if (enter != null) lenC -= enter.length;
        used.value = lenE + lenC;
}
</script>