You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Stephen Moore here.

ASSISTANT: How can I assist you Stephen Moore?

USER: Due to slight changes in my schedule, I want you to help in changing my recent reservation. Can you please help me with that?

ASSISTANT: Sure, I will help you with this. Sorry to inform you, there is no active reservation found under your name in our database.

USER: That's ok, may be something went wrong while I was doing the reservation. Thank you anyways.

ASSISTANT: Thank you for utilising our service.