You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Robert Roberts.

ASSISTANT: How may I help you?

USER: I want to do some changes in my existing reservation. Can you help me for that?

ASSISTANT: Sure Robert, I am here to help you. Let me check your reservation status in our database.

USER: Sure, I will wait for your response.

ASSISTANT: Robert sorry to intimate, no reservation is found on your name in our records.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome.