You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, I am here to help you. Can you please mention your name?

USER: I am Nicole Lopez.

ASSISTANT: Sorry, no reservation found with your given name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for choosing us.