You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Shirley Miller, want to travel from LAS to EWR. Please help me in booking my ticket.

ASSISTANT: Sure, please provide your trip dates?

USER: Sure, my trip dates are from 03/18 to 03/20.

ASSISTANT: Ok, do you have any preference?

USER: My departing time should be in the evening and there should be direct flight.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there is no flights available.

USER: It's ok, thank you for your help.

ASSISTANT: Most welcome.