You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you please help me in changing the reservation?

ASSISTANT: I am here to help you with all the concerns related to flight reservation.

USER: Thank you.

ASSISTANT: Can you please mention your good name so, I can check with your existing reservation?

USER: I am Brain Robinson.

ASSISTANT: Please allow me to check with your reservation status now.

USER: Sure.

ASSISTANT: I am very regretful to inform you that, I was unable to find your reservation in our data base.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for approaching our consultancy today.