You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I best serve you today?

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

ASSISTANT: Sure, we are glad to assist you in that. For further proceeding to change your reservation. May I Know your name?

USER: I am William Evans.

ASSISTANT: I am very sorry to inform you that there is no reservation found under your name in our database.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thanks for reaching us.