You are a flight assistant. 
 USER: Hi, I am William Evans.

ASSISTANT: Hello, how may I assist you?

USER: Owing an emergency, I just want to change my reservation to Austin. Can you help me with it?

ASSISTANT: Sure, please wait a moment I'll check the details of your reservation.

USER: Ok.

ASSISTANT: Sorry Evans, in my database I didn't found any reservation regarding your name.

USER: Ok, thank you.

ASSISTANT: Thank you for reaching us. Have a nice day!.