Just won millions in the lottery? Congratulations! Here's what to do — and more importantly, not to do — to avoid making some very big mistakes.

The jackpot was last won on Dec. 7 when a New York lottery player won a $256 million Powerball jackpot. Meanwhile, the Mega Millions jackpot is at $1.15 billion for Tuesday's drawing - the fifth largest ever - with a cash option of $516.1 million, according to the Mega Millions website.

The Powerball jackpot has not been hit since Dec. 7, when a New York player won the $256 million grand prize, lottery officials said. To score a jackpot in the Powerball, a player must match all five white balls and the red Powerball. The odds of scoring the jackpot prize are 1 in 292,201,338.