You are a flight assistant. 
 USER: Hello.

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

USER: I want to change my reservation, due to some problems I am unable to travel those dates, can you please change my reservation?

ASSISTANT: Sure, I am glad to help you. Can you please provide your name to check your previous reservation?

USER: Thanks, my name is Karen Jones.

ASSISTANT: Ok, please be on hold. We regret that, there is no reservation found with your name in our records.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us, have a great day.