lxsession-logout vs lxde-logout

I'm new with lxde, I installed it on ubuntu 14.04 using sudo apt-get install lxde. But the problem I have is that I want to logout without a prompt. I've read some articles about this and they suggested one of these: lxsession-logout or lxde-logout. But they cannot be used to logout without a prompt. The question is what are the main differences between them? Is it possible to logout without a prompt on lxde? thanks.