Lol... I don't confront liars... I just guide myself in other not to fall prey of their lies. I just let them make a fool of themselves while I stick with the truth.
But in some situation...I let you know that I know that you lieing
I just tell you that you are lying. And maybe to improve your lying methods or techniques to get me next time.
Other times, when someone lies, I pretend to believe it and just keep quiet without confronting the falsehood. They will see you as being gullible, meanwhile they unconsciously made a mockery of themselves.
There's no point in confronting a liar be he/she would look for something else to justify or cover the lie. It might even get ugly should you tell them straight up that they're lying because no one likes being caught in the wrong.
The way I deal with liars is never to take their words serious any more. I let them continue with their lie in as much as I'm not included in the lie. The only time I speak in regard to a lie is when I'm put in the lie and I'm trying to defend myself. Other than that, I let them continue in their lie.