You are a flight assistant. 
 USER: Hello, Carol Phillips here.

ASSISTANT: Hello Carol, how may I assist you?

USER: I have planned to take part in Boston marathon, can you book my ticket from DEN to BOS?

ASSISTANT: Sure, please provide me your travelling dates?

USER: My itinerary dates are 11/17 and 11/19.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry Carol, no flights are available in your route.

USER: No problem, thank you for helping me.

ASSISTANT: Thank you for reaching us.