You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: Can you please book a flight ticket under normal cost from Dallas?

ASSISTANT: Sure, kindly share your travel dates.

USER: My travelling dates are Nov 29 and Dec 01.

ASSISTANT: Do you have any connection limit?

USER: I need a connecting flight.

ASSISTANT: May I know your airport codes?

USER: My airport codes are DEN and DFW.

ASSISTANT: May I know your class preference?

USER: I need a ticket in economy class.

ASSISTANT: Please share your name.

USER: My name is Nicholas Taylor.

ASSISTANT: Ok, please wait a moment.

USER: Take your time.

ASSISTANT: Sorry to say, no flights found with your requirement.

USER: That's ok, thank you for the response.

ASSISTANT: Thanks for reaching us.