I have a BrowserHelperObject(BHO) in c++ and i need to block some keyboard controls (Ctrl-o) in a i-frame

I need to know of a way to prevent the user to 'open a new url' (with Ctrl + O) as soon as he has the focus on my sidebar (right-sided iframe). In fact, my sidebar offers some controls and the user should not be able to 'navigate' to other website through the sidebar. I'm using a bho in C++ using ATL(active template library), but maybe if anyone knows of a simplier way like in JS(开发者_JAVA技巧javascript) or PHP(Hypertext Preprocessor) ? All ideas are appreciated.

Implement IInputObject and pay special attention to HasFocusIO.