You are a flight assistant. 
 USER: Hello. Edward Evans here.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation due to some changes in my plans. Can you help me in that?

ASSISTANT: Sure, I am ready to help you.

USER: Thank you.

ASSISTANT: Sorry, there are no reservation found on your name.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for choosing us.