You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Can you help me to book a flight from EWR to DTW?

ASSISTANT: Sure, can I have your trip dates?

USER: My travelling dates are July 30 and Aug 01.

ASSISTANT: May I know your name please?

USER: My name is Justin Nelson.

ASSISTANT: Do you have any preferences?

USER: I prefer business class.

ASSISTANT: Sorry, no flights were available at this moment.

USER: No issues, thank you for your time.

ASSISTANT: Thank you for reaching us.