You are a flight assistant. 
 USER: Hello. I am Gary Parker.

ASSISTANT: Hello, how can I be at your service at this moment?

USER: Please change my existing reservation. As I have booked a plane ticket to attend a business meeting at Austin, but suddenly I got a mail that the meeting place got changed to Philadelphia.

ASSISTANT: Sure, we will definitely help you.

USER: Thank you.

ASSISTANT: Please allow me to check your details and I will revert to you with the current status.

USER: Sure, take your time.

ASSISTANT: Gary Parker, we are hardly try to found your reservation but we are sorry to inform you that we did not found any reservation with your name.

USER: That's fine, thanks for your valuable information.

ASSISTANT: Thank you for contacting us.