按下按钮以后<a href="[field:arcurl/]">变成了<a href="%5Bfield:arcurl/%5D">
请问怎么让中括号不变成编码?
<body>
<script type="text/javascript" src="http://localhost/leb/auto/js/jquery-latest.js"></script>
<script>
function change(){
var str= $(".test").html();
var reg= /everyone/;
var newstr= str.replace(reg,"world");
$(".test").html(newstr);
}

</script>
<div class="test">
hello everyone!
<a href="[field:arcurl/]">
<img src="[field:litpic/]" alt="[field:title/]" />
</a>
</div>
<button onclick="change()">change</button>
</body>