cortona.Engine.Nodes... doesn't work with Javascript

I started to use this code in 2006 when it was needed to switch
cameras by clicking on scripted links at HTML document with this
Javascript code:
Scene.Engine.Nodes(camera_id).Fields("set_bind")=t rue

Now I read that for version 5.x code should be changed this way:
from:
cortona.Engine.Nodes.Item("SomeShape").Fields.Item ("appearance").Value
to:
cortona.Engine.Nodes("SomeShape").Fields("appearan ce").Value
(http://www.parallelgraphics.com/l2/bin/
vrml_automation_interface_changes.pdf)

But none of this cases works in Opera anymore like it was with
previous versions! Though world loads successful during tests Opera
couldn't find any object in it to operate with JS! Error Console
reports:

Event thread: click
Error:
name: TypeError
message: Statement on line 4: Could not convert undefined or null to
object
Backtrace:
Line 4 of inline#1 script in file://localhost/D:/Work/cortona_eai/index.html
(cortona.Engine.Nodes.Item("S1")).Fields.Item("sta rtA").Value =
true;
Line 1 of script
doit1();
At unknown location
[statement source code not available]

By the way Firefox works well with the same document. I realize that
these browsers based on different engines but is there any way to
solve the trouble in Opera too?