You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation due to postpone of my new house warming ceremony. Could you please help me?

ASSISTANT: Ok, please share your name and let me see if I can help you with it.

USER: Sure, my existing reservation was reserved on name Stephanie Walker.

ASSISTANT: Please wait I will check your reservation and revert back to you soon.

USER: Sure.

ASSISTANT: We didn't find any reservation on your name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you.