You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: Can you please help me to book flight ticket from LAS to BOS?

ASSISTANT: Sure, may I know your travel dates?

USER: My journey dates are Apr 26 and Apr 28.

ASSISTANT: Is there any connection limit?

USER: I prefer a connecting flight.

ASSISTANT: Do you have any other requirements?

USER: I would like to depart in the evening.

ASSISTANT: May I know your name?

USER: Myself Joshua Baker.

ASSISTANT: Sorry, there were no flights found on your route to depart in the evening.

USER: It's ok, thank you.

ASSISTANT: Thank you for contacting us.