You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: Can you please help me in changing my reservation?

ASSISTANT: Sure, I will help you with that. May I know your name please?

USER: I am Andrew Johnson.

ASSISTANT: Please wait for a moment, let me check your previous reservation status.

USER: Ok.

ASSISTANT: Thank you for waiting. There is no reservation found on your name in our database to change.

USER: Ok, no issues. Thank you.

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