diff --git a/core/aes/demo.php b/core/aes/demo.php
index ec0aa1d..8dd060a 100644
--- a/core/aes/demo.php
+++ b/core/aes/demo.php
@@ -2,6 +2,7 @@
 namespace LaneWeChat\Core\Aes;
 include_once "wxBizMsgCrypt.php";
 
+// 第三方发送消息给公众平台
 $encodingAesKey = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFG";
 $token = "pamtest";
 $timeStamp = "1409304348";
@@ -9,13 +10,14 @@ $nonce = "xxxxxx";
 $appId = "wxb11529c136998cb6";
 $text = "<xml><ToUserName><![CDATA[oia2Tj我是中文jewbmiOUlr6X-1crbLOvLw]]></ToUserName><FromUserName><![CDATA[gh_7f083739789a]]></FromUserName><CreateTime>1407743423</CreateTime><MsgType><![CDATA[video]]></MsgType><Video><MediaId><![CDATA[eYJ1MbwPRJtOvIEabaxHs7TX2D-HV71s79GUxqdUkjm6Gs2Ed1KF3ulAOA9H1xG0]]></MediaId><Title><![CDATA[testCallBackReplyVideo]]></Title><Description><![CDATA[testCallBackReplyVideo]]></Description></Video></xml>";
 
+
 $pc = new WXBizMsgCrypt($token, $encodingAesKey, $appId);
 $encryptMsg = '';
 $errCode = $pc->encryptMsg($text, $timeStamp, $nonce, $encryptMsg);
 if ($errCode == 0) {
-    print("加密后: " . $encryptMsg . "\n");
+	print("加密后: " . $encryptMsg . "\n");
 } else {
-    print($errCode . "\n");
+	print($errCode . "\n");
 }
 
 $xml_tree = new DOMDocument();
@@ -28,10 +30,11 @@ $msg_sign = $array_s->item(0)->nodeValue;
 $format = "<xml><ToUserName><![CDATA[toUser]]></ToUserName><Encrypt><![CDATA[%s]]></Encrypt></xml>";
 $from_xml = sprintf($format, $encrypt);
 
+// 第三方收到公众号平台发送的消息
 $msg = '';
 $errCode = $pc->decryptMsg($msg_sign, $timeStamp, $nonce, $from_xml, $msg);
 if ($errCode == 0) {
-    print("解密后: " . $msg . "\n");
+	print("解密后: " . $msg . "\n");
 } else {
-    print($errCode . "\n");
+	print($errCode . "\n");
 }
\ No newline at end of file