diff -r c178e0bdce5d -r 78485949d340 rt/vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java
--- a/rt/vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java	Wed Jul 16 07:57:22 2014 +0200
+++ b/rt/vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java	Sun Aug 10 07:52:49 2014 +0200
@@ -19,6 +19,7 @@
 
 import java.io.IOException;
 import java.io.InputStream;
+import org.apidesign.bck2brwsr.core.JavaScriptBody;
 import static org.apidesign.vm4brwsr.ByteCodeParser.*;
 
 /** Translator of the code inside class files to JavaScript.
@@ -1053,10 +1054,10 @@
                     break;
                 case opc_invokedynamic: {
                     int indx = readUShortArg(byteCodes, i);
-                    System.err.println("invoke dynamic: " + indx);
+                    println("invoke dynamic: " + indx);
                     ByteCodeParser.CPX2 c2 = jc.getCpoolEntry(indx);
-                    System.err.println("  bootmethod: " + jc.getBootMethod(c2.cpx1));
-                    System.err.println("  name and type: " + jc.stringValue(c2.cpx2, true));
+                    println("  bootmethod: " + jc.getBootMethod(c2.cpx1));
+                    println("  name and type: " + jc.stringValue(c2.cpx2, true));
                     emit(smapper, this, "throw 'Invoke dynamic: ' + @1;", "" + indx);
                     i += 4;
                     break;
@@ -2317,4 +2318,9 @@
             append(Integer.toString(cc));
         }
     }
+    
+    @JavaScriptBody(args = "msg", body = "")
+    private static void println(String msg) {
+        System.err.println(msg);
+    }
 }