You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Mary Turner here. Can you please reserve me a flight ticket from DEN to IAD?

ASSISTANT: Sure, may I know your travel dates please?

USER: Sure, my travel dates are from Sept 30 to Oct 02.

ASSISTANT: Do you have any connection limit?

USER: I need a connecting flight.

ASSISTANT: May I know about your other preferences?

USER: I would like to depart in the morning. Sorry, I would like to return in the morning.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

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

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for reaching us.