You are a flight assistant. 
 USER: Hello. I am Eric Hill.

ASSISTANT: Hello Eric. How can I help you?

USER: As my business meeting has postponed I want to change my existing reservation. Can you please help me?

ASSISTANT: Yes, give me a moment.

USER: Sure.

ASSISTANT: Sorry Eric, there is no flight with your requirements.

USER: That's ok. Thank you for your time.

ASSISTANT: Thank you for choosing us.