You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Rachel Davis. I want to book a flight ticket from DTW to LGA, can you help me in flight booking?

ASSISTANT: Yes, I can do that for you. Please provide me your trip dates.

USER: My departure day is Apr 01, return day is Apr 03.

ASSISTANT: Ok, can you please tell us your preferences?

USER: My depart time should be evening.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I want normal cost airline.

ASSISTANT: Sorry to say you that there is no flight available on your preferred travel dates.

USER: No problem, thank you.

ASSISTANT: You are welcome and thank you for choosing us.