You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Benjamin Walker. I want to change my recent ticket details, can you help me?

ASSISTANT: Sure, please wait a moment.

USER: Ok, take your time.

ASSISTANT: Sorry Walker, there is no reservation found on your name.

USER: It's ok, thank you for searching.

ASSISTANT: Thank you for approaching us.

USER: Welcome.