You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I would like to change my existing reservation due to postpone of my conference. Could you please help me?

ASSISTANT: Sure, I will help you. May I know your name to proceed further?

USER: I am Dennis Baker.

ASSISTANT: Please wait a moment while I check the status.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting. Dennis Baker, regret to inform that there is no active reservation found under your name to amend.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us.