You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Sarah Gonzalez.

ASSISTANT: Sarah, how can I assist you?

USER: My business trip was postponed, so I wanted to change my reservation. Can you please help me?

ASSISTANT: Sorry, there is no reservation by your name.

USER: That's fine.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.