You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

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

ASSISTANT: Sure, I will help you in that one. May I know your name please?

USER: Sure, I am Edward Rodriguez.

ASSISTANT: When I have checked there is no reservation found for the user name.

USER: OK, no problem. Thank you for your information.

ASSISTANT: You are welcome.