You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my recent reservation. Can you help me out?

ASSISTANT: Sure, I am here to help you for this. May I know your name please?

USER: Lisa Williams.

ASSISTANT: Please wait for couple of minutes.

USER: Ok, take your time.

ASSISTANT: Sorry for inconvenience, no reservation is found under your name.

USER: That's ok. Anyways, thank you.

ASSISTANT: Thank you very much for contacting our agency.