You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Let me know your name please.

USER: Anthony Hill here.

ASSISTANT: Give me a minute, I will let you know the reservation status.

USER: Sure.

ASSISTANT: Thank you for your time, I could not find any reservation on your name to proceed for modification.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for availing us.