You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Is there any help that you need?

USER: Owing to an emergency I want to change my existing reservation. Can you help me?

ASSISTANT: Sure, I will help you and may I know your name for checking purpose?

USER: Thank you. I am Frank Evans.

ASSISTANT: Thank you for your information, there is no reservation found for the user name in our previous booking list.

USER: Ok, not an problem. Thank you for your valuable information.

ASSISTANT: You are most welcome and thank you for reaching us.