You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Rachel Wilson. I am looking for a flight from OAK to IAD, can you help me in booking the flight ticket?

ASSISTANT: My job is to assist you with the flight ticket booking. Ok, please mention the dates of your journey so I can book.

USER: Sure, my planned travel dates are Feb 18 and Feb 20. I would like to start my journey in the evening flight, can you look for it?

ASSISTANT: Ok, I will check accordingly. Please wait a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry as per the booking portal there is no flight available which starts evening.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for choosing our agency.