You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: Can you please help me in  changing my existing reservation?

ASSISTANT: Sure, I will help you. Please provide your name.

USER: Myself Melissa Davis.

ASSISTANT: Davis, no reservation has been found on your name.

USER: Ok, fine.

ASSISTANT: Thank you for approaching us.

USER: Thank you.