SALISBURY - Grace Britain knows the first thing she'd do if she won the Mega Millions jackpot tonight.

"If I won, I would go on a nice vacation," said Britain, an employee at Salisbury Beverage on Lafayette Road.

The retired man she was selling tickets to yesterday afternoon knew what he'd to as well - faint.

And millions of people are willing to pony up a few dollars on the chance they might find out for real. The Mega Millions jackpot has leaped an estimated $80 million since Tuesday to $330 million, making it the second largest in Mega Millions history. The largest Mega Millions jackpot ever was in March at $390 million, which was split by two people.

The winning numbers of the jackpot will be announced tonight at 11 p.m., and that has people scrambling to get in on the winnings and many N.H. residents coming over the border to buy their tickets in Greater Newburyport, among the highest-selling lottery regions in the state.

All five lottery machines at Marte L's convenience store on Toll Road in Salisbury were buzzing yesterday.

"We have people getting $100 to $150 worth of tickets," manager Nick Partel said.

At Dick's Variety on Plum Island, the third-biggest seller in the state, there was a line stretching from the counter to a freezer that runs along a back wall early in the day, and the store is expecting business to pick up even more in the final hours leading up to the drawing.

There has not been a winner in the 12-state lottery since July 6, or 16 drawings, and as the jackpot has increased, so have the number of players. When the jackpot was a mere $77 million on Aug. 3, it jumped by $12 million by the following Tuesday. From last Friday to this Tuesday, it jumped $44 million, and that will nearly double between Tuesday and tonight.

Mike Partel of Sunny's Convenience Store on Bridge Road said many of the players are newcomers, some of whom need a lesson on playing.

"We get a lot of people who come from out of state and don't understand the lottery," Partel said. "We have to show them how to fill out the cards."

The chances of winning the Mega Millions, in which you must match five numbers and the "Mega Ball," are 1 in 176 million. The $330 million would be paid out over 20 years, but those looking for a one-time payment would get just $194 million.

Colleen Sloane of Newburyport was ready to take her chances yesterday, buying 10 tickets.

"I'd travel and give it away, maybe set up a foundation or something," she said.

Odds of Winning

Matched (Megaball) Chances Winnings

5 (1) 1 in 175,711,536 $330 million

5 1 in 3,904,701 $250,000

4 (1) 1 in 689,065 $10,000

4 1 in 15,313 $150

3 (1) 1 in 13,781 $150

2 (1) 1 in 844 $10

3 1 in 306 $7

1 (1) 1 in 141 $3

0 (1) 1 in 75 $2