Prevent Ctrl+F4 default browser action event in IE11

Question

I am trying to stop or prevent IE11 default behavior of "Ctrl+F4" key. I have tried

        function killKey( event ) {
    event.cancelBubble = true;
    event.bubbles = false;
    event.returnValue = false;
    event.stopPropagation();
    event.stopImmediatePropagation();
    event.preventDefault();
    return false;
    }

function avoidInvalidKeyStorkes(evtArg) {
if(evtArg.which == 115){
//alert("test");
killKey(evtArg);
}
}

if (window.document.addEventListener) {
window.document.addEventListener("keydown", avoidInvalidKeyStorkes, false);
} else {
window.document.attachEvent("onkeydown", avoidInvalidKeyStorkes);
document.captureEvents(Event.KEYDOWN);
}

But still the window got closed when i press Ctrl+F4.

but if i put alert() on top of code, it will work. But without alert() default event not prevented. Can any one suggest me the solution.