use this:
<html>
<head>
<title>unicode converter</title>
<div align=center>
<center>
<table border=0 cellpadding=0 cellspacing=0 style="border-collapse: collapse" width=600 id=AutoNumber1 height=26>
<tr>
<td width=100% height=26>
<p align=center><font face=黑体 size=5 color=#FF0000>unicode 转换工具</font></p>
<p>使用方法:</p>
<p>---在下面的文本框中输入字符,</p>
<p>---按“encode”,可将字符转化为unicode。</p>
<p>---按“decode”,可将unicode还原为字符。</p></td>
</tr>
</table>
</center>
</div>
<p align=center>
<textarea cols=82 rows=10 id=code>
</textarea> </p>
<p align=center>
<input type=button onclick=encode(code) value=encode>
<input type=button onclick=decode(code) value=decode>
<script>
function encode(obj){
obj.value=obj.value.replace(/[^\u0000-\u00FF]/g,function($0){return escape($0).replace(/(%u)(\w{4})/gi,"$2;")});
}
function decode(obj){
obj.value=unescape(obj.value.replace(//g,'%u').replace(/;/g,''));
}
</script></p>