You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: Can you please help me to modify my reservation as my brother got the journey dates wrong?

ASSISTANT: I am happy to help you, may I know your name?

USER: Sure, I am Christopher Adams.

ASSISTANT: I found your reservation, may I know your journey dates?

USER: My trip dates are 10/11 and 10/13.

ASSISTANT: Let me know your locations too.

USER: My airport codes are from AUS to DCA.

ASSISTANT: Is there any time concern?

USER: No, I am fine with any timings.

ASSISTANT: Any other specifications?

USER: No, thanks for asking.

ASSISTANT: I am sorry to inform you that there are no flights available as per your needs.

USER: That's ok, thank you for your information.

ASSISTANT: Thanks for reaching us.