You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Mary Parker.

ASSISTANT: How can I assist you?

USER: I would like to change my reservation, could you help me out?

ASSISTANT: Yes, I can help you. Give me a moment.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: That's ok. Thank you for your time.

ASSISTANT: Thank you for contacting our agency.