You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, may I know your good name?

USER: My name is David Turner.

ASSISTANT: Please wait for a moment.

USER: Ok, I will wait.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us.