AddEventListener() For CtrlEnter Event

Task: I would like to implement a CtrlEnter event that would work on both IE and FF.

My approach: use addEventListener() and attachEvent() to capture the event then trigger a function to check for CtrlEnter:
if (oTarea.addEventListener) {
oTarea.addEventListener('keyup', function() {checkCtrlEnter(event);}, false);
}
else if (oTarea.attachEvent) {
oTarea.attachEvent('onkeyup', function() {checkCtrlEnter(event);});
}

function checkCtrlEnter(e) {
if (e.ctrlKey && e.keyCode == 13) {
// do something
}
return false;
}