You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Can you please book a ticket in a direct flight to reach Seattle?

ASSISTANT: Sure, we are pleased to serve you.

USER: Thank you.

ASSISTANT: May I know your trip dates?

USER: My trip dates are on Feb 4th to 6th.

ASSISTANT: Where you need to catch the flight and land?

USER: My airport codes are IAD - SEA.

ASSISTANT: May I know your depart and arrival time?

USER: I would like to depart in afternoon time.

ASSISTANT: Do you have any other requirements?

USER: I prefer an economy class to go.

ASSISTANT: May I know your good name please?

USER: Sure, my name is Kenneth Martinez.

ASSISTANT: Sorry to inform you that, there are no flights available with your requirements.

USER: Not a problem, thank you.

ASSISTANT: Thank you for reaching us.