//机器人回复
    function xiaoirobot($openid, $content)
    {
        //定义app
        $app_key = "";
        $app_secret = "";

        //签名算法
        $realm = "xiaoi.com";
        $method = "POST";
        $uri = "/robot/ask.do";
        $nonce = "";
        $chars = "abcdefghijklmnopqrstuvwxyz0123456789";
        for ($i = 0; $i < 40; $i++) {
            $nonce .= $chars[ mt_rand(0, strlen($chars) - 1) ];
        }
        $HA1 = sha1($app_key.":".$realm.":".$app_secret);
        $HA2 = sha1($method.":".$uri);
        $sign = sha1($HA1.":".$nonce.":".$HA2);

        //接口调用
        $url = "http://nlp.xiaoi.com/robot/ask.do";
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array('X-Auth:	app_key="'.$app_key.'", nonce="'.$nonce.'", signature="'.$sign.'"'));
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, "question=".urlencode($content)."&userId=".$openid."&platform=custom&type=0");
        $output = curl_exec($ch);
        if ($output === FALSE){
            return "cURL Error: ". curl_error($ch);
        }
        return trim($output);
    }