You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I support you today?

USER: I want to change my existing reservation due to sudden change in my destination point. Can you help me out in my changing my reservation?

ASSISTANT: Sure. May I know your good name please?

USER: I am Gregory Walker.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is a reservation found on your name.

USER: Ok, thank you.

ASSISTANT: Can you please provide your journey details?

USER: My dates of travel are 02/09 - 02/11.

ASSISTANT: Let me know your airport codes.

USER: Houston, TX - HOU is my source code. Washington, DC - IAD is my destination code.

ASSISTANT: Thanks for waiting, there is no flights found on your given requirements.

USER: Ok, I will choose other alternative. Thank you for your quick service.

ASSISTANT: Thank you have a nice day.