微擎验证自带验证码

<form id="form" action="" method="post">

  <div class="form-group">
    <input name="code" type="text" class="form-control" placeholder="请输入验证码" style="width:65%;display:inline;">
<img src="/web/index.php?c=utility&a=code&" class="img-rounded" style="cursor:pointer; width:30%;" onclick="this.src='/web/index.php?c=utility&a=code&' + Math.random();" />
  </div>
  
  <input type="submit" class="btn btn-info btn-block" name="submit" value="立即查询">
  
  <input type="hidden" name="token" value="{$_W['token']}">
  

</form>

php文件

if(checksubmit()){ //验证是否是表单提交
$code = $_GPC['code'];  //接受code
$hash = md5($code . $_W['config']['setting']['authkey']); //微擎验证码加密方式
if($_GPC['__code'] != $hash) { //对比
message('你输入的验证码不正确, 请重新输入.');
}
}