You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Sandra Adams here.

ASSISTANT: Adams, how can I serve you now?

USER: I was made a reservation earlier in this week. But I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, please wait for a while.

USER: Ok, I will wait.

ASSISTANT: No reservation found on your name in our database.

USER: Anyway, thank you for the information.

ASSISTANT: My pleasure, have a great day.