You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Robert Davis here. Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Yes, I can help you.

USER: Thanks.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for contacting us.