diff -r 26513bd377b9 -r 3bd43aa6f08d javaquery/api/src/main/java/org/apidesign/bck2brwsr/htmlpage/api/OnPropertyChange.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/javaquery/api/src/main/java/org/apidesign/bck2brwsr/htmlpage/api/OnPropertyChange.java	Mon Apr 08 12:12:42 2013 +0200
@@ -0,0 +1,38 @@
+/**
+ * Back 2 Browser Bytecode Translator
+ * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. Look for COPYING file in the top folder.
+ * If not, see http://opensource.org/licenses/GPL-2.0.
+ */
+package org.apidesign.bck2brwsr.htmlpage.api;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/** Represents a property. Either in a generated model of an HTML
+ * {@link Page} or in a class defined by {@link Model}.
+ *
+ * @author Jaroslav Tulach <jtulach@netbeans.org>
+ */
+@Retention(RetentionPolicy.SOURCE)
+@Target(ElementType.METHOD)
+public @interface OnPropertyChange {
+    /** Name(s) of the properties. One wishes to observe.
+     * 
+     * @return valid java identifier
+     */
+    String[] value();
+}