You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you at this moment?

USER: I have to change the trip dates because my friend is unable to travel now with us, so we have postponed the trip. Can you please help me to modify the details?

ASSISTANT: Sure, may I know your good name please?

USER: Ok, my name is Christine Smith.

ASSISTANT: Ok, please wait for few minutes.

USER: Sure.

ASSISTANT: There is no existing reservation found on your name in our records.

USER: That's fine, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your help.