You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Joseph Lee.

ASSISTANT: How may I help you?

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

ASSISTANT: Joseph Lee, please wait for a moment.

USER: Ok, take your time.

ASSISTANT: I am so sorry to inform you, there is no flight reservation available by your name.

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

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