You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: My conference has been postponed. I want to change my existing reservation. Can you please help me with that?

ASSISTANT: Sure, could you please provide your name to proceed?

USER: I am Elizabeth Harris.

ASSISTANT: Please wait for a moment, let me check your reservation and revert to you.

USER: Ok.

ASSISTANT: Thanks for waiting, sorry, unfortunately no reservation found on your name.

USER: Ok, no problem. Thanks for your response.

ASSISTANT: Thanks for contacting us.