You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Catherine Adams.

ASSISTANT: How can I assist you today?

USER: I want to change my existing reservation due to postpone of my event at San Francisco. Could you please help me?

ASSISTANT: Sure, I can help you with that. Please let me check your reservation status.

USER: Sure.

ASSISTANT: Catherine Adams, there is no reservation found under your name to do modifications in that.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for choosing us.