You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I want to travel from DFW to ORD. Can you help me to book a flight ticket?

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

USER: I want to fly in the flight on Feb 17 and Feb 19.

ASSISTANT: Do you have any limits on maximum number of connections?

USER: I am looking for a direct flight.

ASSISTANT: Do you have any airline preferences on this journey?

USER: I prefer to travel in normal-cost airline.

ASSISTANT: Do you have any class preferences?

USER: No.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

USER: No.

ASSISTANT: May I know your name for the documentation purpose?

USER: I am Patricia Lee.

ASSISTANT: Unfortunately no flights are available on your specified dates.

USER: That's ok. Anyways, thank you.

ASSISTANT: Welcome, thank you for reaching us.