<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<script language="javascript">
function checkLength(obj){
var count=0;
var inputContent = obj.value;
var total = document.getElementById("total").innerHTML;
var used = document.getElementById("used");
var inputLen = inputContent.length;
var lastLen = 0;
if(lastLen != inputLen){
for(var i=0;i<inputLen;i++){
count = (inputContent.charCodeAt(i)<=256)?(count+1):(count+8);
if(count > total){
obj.value = inputContent.substring(0,i);
count = total;
break;
}
}
used.innerHTML = count;
lastLen = inputLen;
}
}
</script>
</head>
<body>
<table>
<tr>
<td width="400"><textarea onpropertychange="checkLength(this)" oninput="checkLength(this)" style="width: 400px;font-size: 12px;" rows="3" name="comments" id="comments"></textarea>
</td>
</tr>
<tr>
<td>
<span id="used" style="color:#FF0000">0</span>/<span id="total" style="color:#FF0000">1000</span>
</td>
</tr>
</table>
</body>
</html>
ie,ff下测试通过、、、