You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I would like to meet my best friend at Houston, can you help me to book a flight ticket from ORD to HOU?

ASSISTANT: Sure, Can you please share your planned trip dates?

USER: My travelling dates are 12 and 14 of Feb.

ASSISTANT: Do you have any connection limit?

USER: I need a direct flight.

ASSISTANT: Is there any class preference?

USER: I would like to travel in economy class.

ASSISTANT: Are there any other specifications ?

USER: No.

ASSISTANT: Please forward your name.

USER: Nancy Thompson.

ASSISTANT: There are no flights found on your specified travel dates.

USER: It's ok, not a problem, thank you.

ASSISTANT: Thank you for reaching us.