You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Can you please reserve me a flight ticket from DEN to IAD?

ASSISTANT: Sure, may I know your name?

USER: Karen Young here.

ASSISTANT: On which dates are you going to travel?

USER: My trip dates are 09/05 - 09/07.

ASSISTANT: Do you need a single connecting flight?

USER: I need a single connection.

ASSISTANT: Sorry, there are no flights available on your travelling dates.

USER: No issues, thank you.

ASSISTANT: Thank you for choosing us.