You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I want to attend a food festival at Seattle. Can you help me to book a direct flight from DCA to SEA?

ASSISTANT: Sure, I am happy to help you in booking.

USER: Thank you.

ASSISTANT: Can I know your name please?

USER: Myself Charles Thomas.

ASSISTANT: When would you like to depart and arrive?

USER: I will start on Nov, 2 and need to return on Nov, 4.

ASSISTANT: Please provide your specifications.

USER: I want to travel in economy class only.

ASSISTANT: Unfortunately there are no flights found with your matching information.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.