You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER:  I want to book a flight ticket from LGA to SEA. Could you help me in booking?

ASSISTANT: Sure, may I know your planned travel dates?

USER: My travelling dates are Jan,20 and Jan,22.

ASSISTANT: Do you have any specifications on your journey?

USER: My depart time should be in the afternoon.

ASSISTANT: May I know your name for the booking process?

USER: Myself Jonathan Clark.

ASSISTANT: Sorry, no flights are available on your specified dates.

USER: That's ok, thank you for the information.

ASSISTANT: Welcome, thank you for reaching us.