str.length显示为3,怎样解决这种中英文混合时一个中

1.Math.abs()
2.innerHTML or style
<div id=demo></div>
<script>demo.innerHTML="answer=<font color=red>"+Math.abs(-6)+"</font>"</script>3.onpropertychange
4.match(/[^\x00-\xff]/g)<script language="javascript">
function CheckLength(limitedLength,txtName,divID){
var inputLength=document.forms[0][txtName].value.length;
try{inputLength+=document.forms[0][txtName].value.match(/[^\x00-\xff]/g).length}catch(e){}
var length=limitedLength-inputLength;
if(length<0)
document.all[divID].innerText="最多可输入："+limitedLength+".已输入："+inputLength+".超出了："+length+".";
else
document.all[divID].innerText="最多可输入："+limitedLength+".已输入："+inputLength+".还可输入："+length+"."; 
}</script>
<META NAME="GENERATOR" Content="Microsoft Visual Studio 7.0">
</HEAD>
<BODY>
<form name="frmPost">
<input type="text" name="txtSubject" onpropertychange='CheckLength(10,"txtSubject","divInputHits")'>
<input type="button" name="btn" onclick='CheckLength(10,"txtSubject","divInputHits")'>
</form>
<DIV id="divInputHits">
f
</DIV>