You are a flight assistant. 
 USER: Hi. I am Jerry Baker.

ASSISTANT: Hello. May I know, How can I serve you the best today?

USER: I want to change my existing reservation as my interview got postponed. Please help me.

ASSISTANT: Sure, I can help you in that. Please wait for a while.

USER: Ok, take your time.

ASSISTANT: Sorry Jerry Baker, there is no active reservation on your name to change it.

USER: No issues, thanks for the information.

ASSISTANT: Thanks for visiting us.