You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is Melissa Miller. I want to attend for a Cultural program in Denver, so please book a direct flight for me.

ASSISTANT: Sure, help me with your travel dates?

USER: I will start on 11/13, return on 11/15.

ASSISTANT: May I know your travel points?

USER: My source and destination airport codes are NY - JFK to CO - DEN.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT:  Sorry, no direct flights are available on your requested dates.

USER: No problem, thank you for your service.

ASSISTANT: Thank you for opting us.