You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Carol Lopez. Can you help me in Changing my existing reservation?

ASSISTANT: Sure, we can help you. Please wait a moment.

USER: Sure.

ASSISTANT: Unfortunately there is no reservation found on the name Carol Lopez.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing our service.