You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello,.

USER: I am Stephanie Clark.

ASSISTANT: How can I help you?

USER: Can you help me in booking a flight ticket from LAS to BOS?

ASSISTANT: Let me know your travelling dates.

USER: I want to travel on 12/25, and return on 12/27.

ASSISTANT: Do you have any preference?

USER: I want to depart in the afternoon time.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Ok, no issues.

ASSISTANT: Thank you.

USER: Thanks for the information.