You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: Can you please help me in booking from IAD to DEN?

ASSISTANT: Sure, may I know your good name?

USER: My name is Jessica Lee.

ASSISTANT: Could I have your travel dates, please?

USER: My travelling dates are from Feb 22 to Feb 24.

ASSISTANT: Please let me know your connection limit?

USER: I need a connecting flight.

ASSISTANT: Do you have any more specifications?

USER: I prefer economy class.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

ASSISTANT: Sorry, there are no flights available as per your requirements.

USER: Ok, No issues. Thank you.

ASSISTANT: Thank you for opting us.