“This big,” Andy Petty says of the pocketknife found in his car parked at Fayette County High School. He stands in front of the campus that has banned him from setting foot on it, so that he won’t be able to graduate with the rest of the Class of 2006 this year. Petty was ordered to attend Fayette County Alternative School for the rest of the semester, and he worries that might affect his college chances.