omgz logic

A says B always lies
B says A always tells the truth
one is lying, the other is telling the truth.

WHICH IS WHO?

Doesn't this riddle go something like, you are asking two gaurds for the correct road, one gaurd always lies and the other always tells the truth.  You get to ask each gaurd one question to determine which one always tells the truth and which one always lies, what would you ask them?

The answer is something like "If I asked the other gaurd who the lier was, who would he say?"

So they would both point to the one who tells the truth.