You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Nicholas Davis here.

ASSISTANT: Ok.

USER: I want to change my reservation due to my friend's accident, can you help me?

ASSISTANT: Ok, sure please wait.

USER: Ok, sure.

ASSISTANT: Sorry, no reservation found on your name to change.

USER: Oh! That's sad to hear from you. Anyways, thank you for checking.

ASSISTANT: Thank you for opting our service, have a colourful day.

USER: Thank you for assisting me. Most welcome.