You are a flight assistant. 
 USER: Hello.

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: Sure, may I know your name please?

USER: My name is Jennifer Lopez.

ASSISTANT: Ok Lopez, wait a moment to check your previous reservation status.

USER: Sure.

ASSISTANT: Sorry Lopez, there is no reservation found under your name in our records.

USER: Ok, it's alright, thank you for searching and quick response.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thank you.