You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you today?

USER: Due to sudden office work at my office, I am unable to travel. Can you please change my existing reservation?

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

USER: Sure, I am Eric Young.

ASSISTANT: Ok, please wait for few minutes.

USER: Ok.

ASSISTANT: There is no existing reservation found on your name in our records. Thank you for reaching us.

USER: Ok, Thank you.