Infosys Logic Interview Question

This was asked in an interview of Infosys.

Interviewer has given me 100 marbles(50 white and 50 black) and two empty boxes.
He then told me that he will leave the room and i need to place all the marbles in two boxes.

And When he come back, he will draw a marble from any of the two box and if the marble is black i will be hired.

Also
* No box can be empty.
* All 100 marbles must be placed in one of the two boxes.

So whats should i have done ?