You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I want to visit the White house in Washington DC. Can you help me to book the flight ticket?

ASSISTANT: Sure, I will help you out in the this.

USER: Thank you.

ASSISTANT: May I know your source and destination airport codes?

USER: Sure, I will like to fly from PHL and my destination code is IAD.

ASSISTANT: Please kindly, provide me your travel dates of your trip?

USER: Ok, my depart date is 09/25 and return date is 09/27.

ASSISTANT: Please wait a moment, let me check the flights in your route.

USER: Sure.

ASSISTANT: Here is a flight with 1 connection limit and airfare is 100. Is it comfortable to you?

USER: No, I am looking for a direct flight. Can you aid me with that?

ASSISTANT: May I know your name.

USER: Yes, my name is John Harris.

ASSISTANT: Sorry John, no flight with 0 connection limit in our airline.

USER: That's ok, no problem. Thank you for your assistance.

ASSISTANT: Welcome, thank you for reaching us.