You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I have some personal matters that need fixing, so I need to change an existing reservation. can you please help me to change reservation?

ASSISTANT: Sure. Can you please provide your good name?

USER: My name is Sandra Clark.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to inform you, We did not found any reservation on your name.

USER: That's not a problem. Thank you.

ASSISTANT: Thanks for connecting to us.