printf("aEvent->message %d on 0x%X\n", aEvent->message, aEvent->widget);
nsEventStatus PR_CALLBACK HandleEventButton(nsGUIEvent *aEvent){    printf("aEvent->message %d on 0x%X\n", aEvent->message, aEvent->widget);    switch(aEvent->message) {        case NS_MOUSE_LEFT_BUTTON_UP:            scribbleData.drawPane->Invalidate(PR_TRUE);    }    return nsEventStatus_eIgnore;}