You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: Timothy Jonhson here. Please help me out in booking the ticket from EWR to JFK.

ASSISTANT: When you are planning to go?

USER: My trip dates will be Apr 16 to Apr 18.

ASSISTANT: May I know your airline preferences?

USER: No airlines preference is required.

ASSISTANT: Is there any other requirements?

USER: My return time must be in the evening.

ASSISTANT: Sorry, we don't have any flight available for your trip.

USER: That's ok, thank you.

ASSISTANT: Thanks for choosing us.