You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist 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 name for checking previous reservation in our database?

USER: My name is Cynthia Hall.

ASSISTANT: Please wait for a moment.

USER: Ok, I will wait.

ASSISTANT: Sorry to inform you that, there is no reservation found in our database.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us with a query.