You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: My name is Richard Thompson. I am looking to book a flight ticket to meet my friend in Philadelphia. Can you help me for booking a flight ticket from ORD to PHL?

ASSISTANT: Sure, when would you like to depart and return?

USER: My travelling dates are Nov 24 and Nov 26.

ASSISTANT: Do you want connecting flight?

USER: I need a single connecting flight.

ASSISTANT: Do you have any class preference?

USER: Any class fine for me.

ASSISTANT: Ok, how much you can afford for flight ticket?

USER: I can afford up to 500.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: That's ok, I will choose any other way to reach my destination on time. Anyway thank you for checking.

ASSISTANT: Thank you for opting us.