You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Karen Hernandez here.

ASSISTANT: How can I assist you?

USER: I would like to celebrate this Christmas with my family at Seattle, please help me in booking a ticket from BOS to SEA.

ASSISTANT: Sure, I can help you with that. May I know your planned travel dates please?

USER: My planned travel dates are Dec 25 and Dec 27.

ASSISTANT: Ok, in which class you want to travel?

USER: Any class is comfortable for me.

ASSISTANT: Ok, please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry to inform you that there are no flights available for you on those dates.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for reaching us.