You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Raymond Johnson.

ASSISTANT: How can I assist you?

USER: Can you check any flight is available on 04/16 to 04/18, as there is a client meeting?

ASSISTANT: Yes, I am here to help you. May I know your airport codes to check for the flight availability?

USER: My source is DTW and destination is SFO.

ASSISTANT: Sorry Raymond Johnson, there is no flight available at those dates. Regret for the inconveniences caused.

USER: No issue, thank you for checking.

ASSISTANT: Thank you for availing our agency.