21. The delegates in Brussels say single-cigarette sales foul up their " tax harmonization " plans. 22. Left unchecked, the date confusion could foul up banking, insurance and transportation-scheduling systems, among others. 23. Data entry errors by IRS personnel foul up an estimated 1O percent of returns annually. 24. These are the things the Rockets'didn't foul up during their championship run of a season ago. 25. "He said, ` Experience is when you foul up , you know how to handle it .' 26. Leave it to Beavis and Butt-head to foul up their assignment, leaving them marked for murder. 27. To foul up on the athletic field is to feel the repercussions swiftly and sometimes acutely. 28. Steaks and chops are difficult to foul up . 29. This is too important to foul up . 30. A related strategy is to foul up the ball and intentionally serve it into your opponent's cup.