You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: My name is Sandra Green. I would like to travel from PHl to IAD, could you help me out?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: My preferable dates are from 08/22 to 08/24. That's ok.

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

USER: Thank you for your time.

ASSISTANT: Thank you for reaching us.