You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Shirley Turner. Can you help me in changing my previous reservation?

ASSISTANT: Sure, please give me a minute to check the database.

USER: Sure, take your time.

ASSISTANT: Sorry Shirley, there is no reservation found according to he database.

USER: That's fine. Anyway, thank you for your help.

ASSISTANT: You are most welcome.