You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: Can you please assist me to change my active my active reservation?

ASSISTANT: Sure, please share me your good name.

USER: David Clark.

ASSISTANT: Please wait for a while.

USER: Ok, no problem.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.