You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I would like to change my journey date. Please help me in changing my existing reservation.

ASSISTANT: Sure, can I know your name please?

USER: My name is Steven Edwards.

ASSISTANT: Sorry Steven, there is no reservation found on your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for approaching us.