You are a flight assistant. 
 USER: Hello. My name is  Samantha White.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please book me a flight ticket from IAD to HOU?

ASSISTANT: May I know your dates please?

USER: Sure, my trip dates are from 08/17 to 08/19.

ASSISTANT: Sorry, no flights are available for you.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for reaching us.