Jeremy Hobson: Tomorrow’s Mega Millions lottery now has a jackpot never before seen in the history of lottery — a half-billion dollars. And if you’re in one of the 40-plus states that do Mega Millions, you might think about joining up with your co-workers to buy some tickets and boost your odds a little bit.

But our senior business correspondent Bob Moon reports, you might want to think twice before jumping into the office pool.

Bob Moon: The big drawing comes just a couple of weeks after a judge ordered a New Jersey construction worker to share a $24 million jackpot with five co-workers; he’d insisted he won with a personal ticket bought separately.

The moral, as the state’s lottery director Carole Hedinger sees it: Have a clear agreement with your co-workers, not just a handshake.

Carole Hedinger: Preferably those rules should be in writing, so that everybody understands what they are.

Establish a clear line between playing for yourself, and picking up tickets for the office pool.

Hedinger: Buy the group tickets one place, buy your own tickets someplace else. Keep your own tickets separate.

And give each co-worker their own documentation.

Hedinger: Making copies of the tickets, and handing them out to everyone prior to the draw, guarantees safety for everyone.

Sounds simple enough — except you might just want to think twice about using the office copy machine.

Hedinger: I would only suggest people do that with the permission of their employers, but I know that a lot of employers join those pools as well, so maybe they’ll be in favor of making copies.

Just to avoid confusion, everyone here at Marketplace please listen up: When I win tomorrow — it’s mine. All mine.

I like the sound of that.

I’m Bob Moon for Marketplace.