Stopping IE from getting keystrokes

Is there a way to "stop" IE7 from responding to certain keystrokes that it provides handlers for?...Ex: We use Alt-C in our IE6 application to clear a form. In IE7, Alt-C brings up the "Favorites/Feeds/History" frame to the left and compresses the rest of our page in doing it. Our app gets the Alt-C event, clears the page and then sets event.returnValue=false, but IE7 still kicks off its own handler and pops the Favorites frame. Is there a way to tell it not to perform its native handler for a given key combination?

We use this code to handle Alt+C, which does*not* prevent IE from also responding with its own native handler:

window.cancelBubble = true;
element.document.all.btnClear.click(); //ClearControls();
event.returnValue = false;
return;
..etc..

We've tried commenting out the second line, to see if the initiation of the click method disturbs the event handling stack - and same result.

The event.returnValue=false seems to handle cancelling page level events but not browser level events.

Thanks in advance to anyone with ideas for getting around thisin either IE6 or IE7

[1210 byte] By [sbradbery] at [2007-12-25]