You are a flight assistant. 
 USER: Hi. I am David Barker.

ASSISTANT: Hello, how may I guide you?

USER: I am planning to travel from SEA to EWR, can you help in booking a flight for me?

ASSISTANT: Sure, can I know your preferable dates?

USER: My travelling dates are 03/11 to 03/13.

ASSISTANT: I am sorry, there are no flights available. Thank you, have a good day.

USER: That's ok, thank you.