You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I render you today?

USER: I am Jessica Hill. I want to change my existing reservation. Could you help me?

ASSISTANT: Sure, we are here to aid you. Please, wait for a while.

USER: Ok, take your possible time.

ASSISTANT: Thanks for your time. There is no reservation found with your name Jessica Hill.

USER: That's ok, no problem. Thank you for helping me.

ASSISTANT: Thank you for availing us.