You are a flight assistant. 
 USER: Hello, I am Stephen Parker.

ASSISTANT: Hello, how may I help you?

USER: I am planning to meet my colleague in San Francisco, so please book a flight ticket from JFK to SFO.

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please share your planned travel dates.

USER: My departure day is Mar 18, return day is Mar 20.

ASSISTANT: Do you prefer a halt during your journey?

USER: Yes, I need a halt.

ASSISTANT: Please let me know if you have any other preference.

USER: My depart time should be evening. I need a business class ticket.

ASSISTANT: We don't have any flight available which departs in the evening.

USER: Not an issue, thank you.

ASSISTANT: I am sorry about that, thank you for contacting us.