You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I am planning to change an exiting reservation, due to some urgent work. Can you please help me out?

ASSISTANT: Sure, may I know your name?

USER: My name is Sandra Garcia.

ASSISTANT: Ok, please wait for a minute.

USER: Sure, I will wait for your reply.

ASSISTANT: Sorry, we couldn't find a reservation on your name in the database.

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

ASSISTANT: Thank you for approaching us.