add demo
diff --git a/demo/main.cpp b/demo/main.cpp
new file mode 100644
index 0000000..8f24743
--- /dev/null
+++ b/demo/main.cpp
@@ -0,0 +1,11 @@
+#include<QApplication>
+#include "chatdialog.h"
+
+int main(int argc, char *argv[]) 
+{
+  QApplication app(argc, argv);
+  
+  ChatDialog dialog;
+  dialog.show();
+  return app.exec();
+}