You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I be a help for you?

USER: I am Benjamin Smith, can you help me searching flights from IAD to JFK?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Can you please share your preferable dates to travel?

USER: My preferable travelling dates 04/10 and 04/12.

ASSISTANT: Sorry for the inconvenience, there is no flight available in this route on your requested dates.

USER: Oh! It is ok, thank you for your services.

ASSISTANT: Most welcome. Have a great day.