You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I want to change my existing reservation, due to some health issue. Can you please help me with this?

ASSISTANT: Sure, I am oblige to help you and can I know your name please?

USER: Sure, I am Nicholas Walker.

ASSISTANT: Thank you for your information, I found your reservation on your name. Can you please provide your new airport codes?

USER: My journey airport codes are SEA and IAD.

ASSISTANT: Can you please provide your desired travel dates?

USER: My depart date is on Feb 27 and return date is on Feb 29.

ASSISTANT: Can I know your in between connections in your journey?

USER: I would like to travel in single connected flight.

ASSISTANT: Please allow me a moment.

USER: Ok.

ASSISTANT: I regret to inform you that there is no flight obtained on your journey dates to book a flight ticket.

USER: Ok, Thank you.

ASSISTANT: You are most welcome and thank you for reaching us.