diff -r 000000000000 -r a0f15cb8c730 chat/js/src/main/java/org/apidesign/demo/chat/js/Dialogs.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/chat/js/src/main/java/org/apidesign/demo/chat/js/Dialogs.java	Fri Apr 22 05:56:47 2016 +0200
@@ -0,0 +1,45 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (C) 2013 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.apidesign.demo.chat.js;
+
+public final class Dialogs {
+    private Dialogs() {
+    }
+    
+    /** Shows confirmation dialog to the user.
+     * 
+     * @param msg the message
+     * @param callback called back when the use accepts (can be null)
+     * @return true or false
+     */
+    @net.java.html.js.JavaScriptBody(
+        args = { "msg", "callback" }, 
+        javacall = true, 
+        body = 
+            "var ret = confirm(msg);" +
+            "if (ret && callback) callback.@java.lang.Runnable::run()();" +
+            "return ret;"
+    )
+    public static native boolean confirm(String msg, Runnable callback);
+}