You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Melissa Miller. Can you help me in booking the ticket from SFO to DEN?

ASSISTANT: Sure, can you please share your travel dates?

USER: My planning dates are from 11/13 to 11/15.

ASSISTANT: Let me check for the availability of flight.

USER: Ok.

ASSISTANT: Melissa, there is no flight available at your requested dates.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.