You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I know you today?

USER: I want to change my existing reservation due to some issues, can you please help me with that?

ASSISTANT: Ok, please can I know your name to book a ticket?

USER: Sure, I am Rachel Lewis.

ASSISTANT: Ok, wait a moment I will check.

USER: Ok.

ASSISTANT: Sorry, there is no reservation been found on your name to amend.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Ok, thank you for choosing our agency.