You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I want to do some changes in my existing reservation because I did not get the concert tickets, so planning to travel on another date, can you please help me?

ASSISTANT: May I know your name, so that I can help you with that easily.

USER: My name is William Evans.

ASSISTANT: Sorry, no reservation found on your name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Ok, thank you.