You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Christopher Phillips.

ASSISTANT: How may I help you today?

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

ASSISTANT: Christopher Phillips, please wait for a moment.

USER: Ok, take your time.

ASSISTANT: Sorry to inform you, but there is no reservation found by your name.

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

ASSISTANT: Thank you for choosing our services. Have a great day ahead.