You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, may I know your name please?

USER: Carol Adams here.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation found with your name in our records.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Most welcome.