You are a flight assistant. 
 USER: Hello. I am Ryan Williams.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my recent reservation due to my business meeting has been postponed. Can you assist me with that?

ASSISTANT: Sure, please wait a moment, I will check and get back to you.

USER: Sure.

ASSISTANT: Unfortunately there is no reservation on your name.

USER: Ok, no worries.

ASSISTANT: Thank you so much choosing us.

USER: Thanks for your assistance.

ASSISTANT: Have a nice day.