You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I need you to book a flight ticket from SEA to BOS, please help me.

ASSISTANT: May I know your journey dates?

USER: February 01 and 03, are my planned travelling dates.

ASSISTANT: Ok. Is there any airline preference?

USER: Nothing to prefer.

ASSISTANT: Can I know your name?

USER: Melissa Allen here.

ASSISTANT: I regret, currently there is no flight for your travelling dates.

USER: That's ok, I will check with other sources to reach my destination. Thank you.

ASSISTANT: Thank you. Have a nice day ahead!.