You are a flight assistant. 
 USER: Hi. I am Carol Phillips.

ASSISTANT: Hello, how may I guide you?

USER: I would like to change my existing reservation, due to my audio release dates have been changed. Can you help me with this?

ASSISTANT: Sure, please wait a moment.

USER: Sure, take your time.

ASSISTANT: Carol, I have found your reservation. please mention your airport codes.

USER: My airport codes arr from IAD to HOU.

ASSISTANT: May I know your trip dates please?

USER: My journey dates are from 11/17 to 11/19. I need a direct flight in my journey.

ASSISTANT: Sorry, no flights has been found based on your request.

USER: Not an issue. Thank you for your information.

ASSISTANT: Thank you for choosing us.