You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I would like to change my existing reservation, can you please help me in changing?

ASSISTANT: Sure, may I know the name to check for the status?

USER: Christopher Moore.

ASSISTANT: Please be on hold, I will get back to you in a minute.

USER: Sure.

ASSISTANT: Thank you for waiting. Here, there is no active reservation have been found under your name in our database to amend it.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.