You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I want to meet my sister, could you book my ticket from IAD to DEN?

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

USER: My itinerary dates are Mar 19 and 21.

ASSISTANT: Do you have any connection limit?

USER: I need a connecting flight.

ASSISTANT: Is there any other requirements, please let me know?

USER: I have no other preferences.

ASSISTANT: Can you please share me your name?

USER: Patricia Taylor here.

ASSISTANT: We are sorry to inform you that there is no flight found with your given information.

USER: No problem, thank you.

ASSISTANT: Thank you for opting us.