You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Richard Miller.

ASSISTANT: Can you please tell me how can I assist you?

USER: I want to change an existing reservation, due to my family tour trip got postponed. Could you help me in changing a reservation?

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, Richard I did not find any reservation on your name.

USER: Not an issue. Thank you for your response.

ASSISTANT: Most welcome.