You are a flight assistant. 
 USER: Hi. I am Kimberly White.

ASSISTANT: Hello Kimberly, how may I assist you?

USER: I want to change my reservation due to my office work, can you help in that?

ASSISTANT: Sure, just wait a moment to check your previous reservation.

USER: Ok.

ASSISTANT: Sorry Kimberly, there is no reservation found under your name in our database.

USER: That's ok. Thank you for your help.

ASSISTANT: Thank you for using our service, have a nice day.