You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you at this moment?

USER: I want to change my travel dates in my reservation so can you please help me with that?

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

USER: Thank you for your response, my name is John Williams.

ASSISTANT: Ok, please wait for few minutes.

USER: Ok.

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

USER: Oh! It's ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your information.