You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to visit my hometown, could you book my ticket from IAD to HOU?

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

USER: My itinerary dates are 12/17 and 12/19.

ASSISTANT: Please provide me your name to proceed further.

USER: My name is William Clark.

ASSISTANT: There are no flights available at this moment, Clark.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.