diff --git a/projects/IoTCenter/wwwroot/js/message.js b/projects/IoTCenter/wwwroot/js/message.js
index 5ef1b22f..04bec9cc 100644
--- a/projects/IoTCenter/wwwroot/js/message.js
+++ b/projects/IoTCenter/wwwroot/js/message.js
@@ -1,6 +1,5 @@
 var connection = new signalR.HubConnectionBuilder().withUrl(hubUrl).build();
 var connectionId;
-var connectionKeeper;
 function connect() {
     console.log('check connection state :' + connection.state);
     if (connection.state === signalR.HubConnectionState.Disconnected) {