You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I just want to change an existing reservation as my meeting got post pone due to some technical issues. Can you help me with this?

ASSISTANT: Sure, We are here to assist you.

USER: Thank you.

ASSISTANT: Can I know your name?

USER: I made a reservation by this name Raymond Allen.

ASSISTANT: Please wait a while.

USER: Sure.

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: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.