You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

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

ASSISTANT: How can I help you? Sure, just a moment please.

USER: Ok, I will wait.

ASSISTANT: I am sorry no reservation on your name.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing us.