You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: I want to book a direct flight ticket to attend an emergency case at CO. Can you help me?

ASSISTANT: Sure, can you share your trip dates?

USER: Sept 28th and 30th are my travelling dates.

ASSISTANT: Kindly, mention airport codes.

USER: OAK and DEN are my airport codes.

ASSISTANT: Do you have any connection limit?

USER: I need a direct flight.

ASSISTANT: Is there any class preference?

USER: No.

ASSISTANT: Please forward your name.

USER: Deborah Lewis here.

ASSISTANT: Sorry, there are no flights found on your specified trip dates.

USER: No issue, Thank you.

ASSISTANT: Thank you for availing us.