[Sasuke]

I would like to know if both these two sentences are acceptable/correct or incorrect.

John, who you met yesterday, is my father.

or

John, whom you met yesterday, is my father.

In the main proposition John is, without doubts, the subject.
But in the relative, shall I use whom or who?

And, again:

I have found a man who will complete the work.

or

I have found a man whom will complete the work.

In this case the subject is me (I) and the man is the object...
So, do I have to use who or whom?
I suppone whom to be wrong in the second sentence, but I am not completely sure.

Thanks!