You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation due to postpone of my client meeting, can you please help me with that?

ASSISTANT: Sure, can you please provide me your name?

USER: My name is Elizabeth Williams.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT:  Elizabeth Williams. I regret to inform that there is no reservation by your name.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.