catch the js onbeforeUnload in c++

[daka1]

Hello,
Is there a way I can easily catch the onBeforeUnload event from js in c++ code.

For instance if I want to kill some child process when the JS-page unloads.

I saw this: http://www.magpcss.org/ceforum/viewtopi ... =6&t=12598
Where can i extend this method? client_handler.cc?