You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I oblige you today?

USER: I want to change my existing reservation as my scheduled plan of journey was changed. Will you help me in changing my reservation?

ASSISTANT: Sure, I will help you to change your reservation. May I know your name?

USER: I am Elizabeth Evans.

ASSISTANT: Please wait for a moment, while I check for the reservation.

USER: Sure.

ASSISTANT: Thanks for waiting, sorry there is no reservation found on your name in our system data.

USER: Ok, no issues. Thank you for quick service.

ASSISTANT: Thank you for visiting us, have a nice day ahead.