I booked this trip many months in advance using frequent flier miles. As our travel date approached I realized that we had a 5 hour lay over at Dulles before the 24 minute flight into Harrisburg. I called United to request an earlier flight. One was available but the agent I spoke with had difficulty understanding my request. After at least 40 minutes on the phone with many "put on hold" the agent offered us the earlier flight for $250.00 additional. I terminated the call and took a prearranged United review on line. Within an hour another United agent called my home. When I explained my request she said" I can do that". Thank you, United. You have a happy passenger..