[Javascript]UTF-8编码解码

<input id="decode" name="lang" onclick="refresh()" type="radio" checked/>
<label for="decode" title="decode">解码</label>
<input id="encode" name="lang" onclick="refresh()" type="radio" />
<label for="encode" title="encode">编码</label>
<textarea style="width:80%;height:200px;" onkeyup="refresh();" id="toutf-8"></textarea>
<pre><code id="result" name="result"></code></pre>
<script>
var refresh = function()
{
	if(document.getElementById('decode').checked){
		document.getElementById("result").textContent="";
		var s=document.getElementById("toutf-8").value;
		var a=s.split(/%(?![A-Fa-f0-9]{2})/);
		for(i=0;i<a.length;i++){
			document.getElementById("result").textContent+=(decodeURIComponent(a[i]));
			if(i!=a.length-1)
				document.getElementById("result").textContent+="%";
		}
	}
	else document.getElementById("result").textContent=encodeURIComponent(document.getElementById("toutf-8").value);
}
refresh();
</script>