diff --git a/ChatController/ChatMainControl.xaml.cs b/ChatController/ChatMainControl.xaml.cs
index 1a57df4..bef8dc8 100644
--- a/ChatController/ChatMainControl.xaml.cs
+++ b/ChatController/ChatMainControl.xaml.cs
@@ -7,6 +7,7 @@ using System.IO;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Text;
+using System.Threading;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Data;