You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Stephen Collins.

ASSISTANT: How can I help you today?

USER: I would like to book a flight ticket from LGA to DTW, can you please help me to book a flight ticket?

ASSISTANT: Sure, can you share me your trip dates?

USER: Sure, my travelling dates are Mar 22 and Mar 24.

ASSISTANT: Do you have any specifications?

USER: My return time is afternoon and my airline preference is normal-cost.

ASSISTANT: Sorry, no flights are available on your travel dates.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for reaching us.