You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I help you for today?

USER: I am Mary Thompson from Washington. I have to go Chicago next month, can you please book a flight ticket for me?

ASSISTANT: I will try my best to guide you about your flight ticket booking.

USER: Thank you.

ASSISTANT: Can you please help me with your planned dates of journey?

USER: I want to take off on 10/23 and book my return ticket also on 10/25.

ASSISTANT: Can you please help me with your respective location points where you want to board and takeoff?

USER: I would like to fly from IAD airport and destination airport is ORD because these two airports are very convenient for me to travel.

ASSISTANT: Hold on for some time I will get back to you with the best flight for your journey.

USER: Sure.

ASSISTANT: Sorry Mary, there is no flights for your journey on your planned dates of journey.

USER: Oh! no problem, I will contact another agency. Thank you for your service.

ASSISTANT: Ok, have a try there. Most welcome, hope you have a nice day.