You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you for today?

USER: Myself Nancy Wilson. For some personal issues I want to change my reservation, can you please help me?

ASSISTANT: Sure, I will help you about it. But, Nancy there is no reservation in our database that you have done booking.

USER: Ho! I see, I think I didn't reserved my ticket properly. It's ok, thank you for the information.

ASSISTANT: Sorry, to say this.Hope you have a good day a head.