You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Please help me to book a flight ticket from SEA to DEN.

ASSISTANT: Can you mention your trip dates?

USER: My travel dates are from May, 20 to May, 22.

ASSISTANT: Do you need any connections?

USER: I need a direct flight.

ASSISTANT: Are there any other preferences?

USER: I prefer an economy class to fly.

ASSISTANT: May I know your name?

USER: Carol Edwards.

ASSISTANT: Sorry, there is no flight found with your details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.