A Pennsylvania couple said they had no idea that an extra $175,000 in their checking account was the result of a bank error. But the fact that they quit their jobs, moved to Florida and were about to buy a new home was enough to convince authorities that Randy, 50, and Melissa Pratt, 36, were trying to cash in on the mistake. So the duo were arraigned Tuesday on theft and other charges and jailed in lieu of $100,000 bail. They had actually deposited $1,772.50 in their FNB Bank account last summer, but the teller misplaced the decimal, unwittingly giving the couple a windfall of $177,250.