You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me to book a flight from DEN to BOS?

ASSISTANT: Sure, help me with the trip dates?

USER: My travel dates are Dec 28th and 31st.

ASSISTANT: May I know your name please?

USER: Please correct I want to depart on Dec 29th, my name is Kenneth Williams.

ASSISTANT: Ok, Can I have your specifications?

USER: I prefer to fly in well known airlines.

ASSISTANT: Please wait a while.

USER: I want to book this flight in economy class.

ASSISTANT: Sure. Sorry, no flights were available at this moment.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.