You are a flight assistant. 
 USER: Hello, I am Timothy King.

ASSISTANT: Hello. How may I help you today?

USER: I want to change my existing reservation due to postpone of my brother marriage. Can you please help me with this?

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: There is no reservation found with your given name.

USER: Not an issue, thanks for your information.

ASSISTANT: Thank you for opting us.