diff --git a/include/web-socket-js/sample.html b/include/web-socket-js/sample.html
index a2883b1c..4dbdbe84 100644
--- a/include/web-socket-js/sample.html
+++ b/include/web-socket-js/sample.html
@@ -1,6 +1,5 @@
 <!--
-  Copyright: Hiroshi Ichikawa <http://gimite.net/en/>
-  Lincense: New BSD Lincense
+  Lincense: Public Domain
 -->
 
 <html><head>
@@ -36,6 +35,9 @@
       ws.onclose = function() {
         output("onclose");
       };
+      ws.onerror = function() {
+        output("onerror");
+      };
 
     }
     
