You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: Is it possible for you to change my reservation which I have done recently?

ASSISTANT: Sure, kindly share your name.

USER: My name is Katherine Roberts.

ASSISTANT: Please wait a moment I will check the reservation and get back to you.

USER: Ok.

ASSISTANT:  We have gone through the reservation list but could not find reservation with your name.

USER: No problem, thank you anyway.

ASSISTANT: Thanks for choosing us.