You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: Can you please change my recent reservation? As my planned trip has been postponed to some other dates.

ASSISTANT: Sure, We are here to help you. May I know your name?

USER: Sure, my name is Joshua Brown.

ASSISTANT: Give me a minute.

USER: Sure, I'll wait for your response.

ASSISTANT:  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: That's ok, thank you for giving the information.

ASSISTANT: Thank you for reaching us.