You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Sarah Adams.

ASSISTANT: How can I guide you today?

USER: I want to do some changes in my existing reservation, can you help me for that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Ok, take your time.

ASSISTANT: Sorry to inform you Sarah, there is no reservation found with your name in our records.

USER: That's ok, thank you for checking.

ASSISTANT: Welcome, thank you for choosing us.