You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am Benjamin Evans, I want to book a flight ticket to IAH from ATL.

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Sure, my travelling dates are 04/16 and 04/18.

ASSISTANT: Sorry, there are no flights found in our database.

USER: Not a problem, anyway thank you for the help.

ASSISTANT: Thank you for reaching us.