diff -r 859804c78010 -r 39166e462f8d rt/launcher/src/main/java/org/apidesign/bck2brwsr/launcher/impl/FXBrwsr.java
--- a/rt/launcher/src/main/java/org/apidesign/bck2brwsr/launcher/impl/FXBrwsr.java	Thu Mar 14 09:22:28 2013 +0100
+++ b/rt/launcher/src/main/java/org/apidesign/bck2brwsr/launcher/impl/FXBrwsr.java	Wed Mar 20 06:56:44 2013 +0100
@@ -111,6 +111,10 @@
             eng.setOnAlert(new EventHandler<WebEvent<String>>() {
                 @Override
                 public void handle(WebEvent<String> t) {
+                    if ("bck2brwsr".equals(t.getData())) {
+                        initBck2Brwsr(eng);
+                        return;
+                    }
                     JOptionPane.showMessageDialog(null, t.getData());
                 }
             });
@@ -128,25 +132,10 @@
         void initBck2Brwsr(WebEngine webEngine) {
             JSObject jsobj = (JSObject) webEngine.executeScript("window");
             LOG.info("window: " + jsobj);
-            System.getProperties().put("webEngine", webEngine);
-            Object prev = jsobj.getMember("jvmBridge");
-            if (prev instanceof JSObject) {
-                jsobj.setMember("jvmBridge", bridge);
-                JSObject jso = (JSObject) prev;
-                Object len = jso.getMember("length");
-                if (len instanceof Integer) {
-                    for (int i = 0; i < (Integer) len; i++) {
-                        Object slt = jso.getSlot(i);
-                        if (slt instanceof String) {
-                            try {
-                                bridge.loadClass((String) slt);
-                            } catch (ClassNotFoundException ex) {
-                                LOG.log(Level.SEVERE, null, ex);
-                            }
-                        }
-                    }
-                    LOG.info("bck2brwsr: " + jsobj.getMember("bck2brwsr"));
-                }
+            Object prev = jsobj.getMember("bck2brwsr");
+            if ("undefined".equals(prev)) {
+                System.getProperties().put("webEngine", webEngine);
+                jsobj.setMember("bck2brwsr", bridge);
             }
         }