You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, How may I assist you ?

USER: I want to change my existing reservation as my meeting venue got changed. Can you help with changing my reservation?

ASSISTANT: Sure, I will check the database, please provide your name.

USER: I am Stephanie Carter.

ASSISTANT: Thanks for sharing, no reservation is existed with your name.

USER: Ok, no issues.

ASSISTANT: Thank You.

USER: Thank you for best service.