You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, what help are you expecting from our agency?

USER: Can you please book a flight ticket from SFO to DEN?

ASSISTANT: When your you planning to visit Denver for this journey?

USER: I want to travel in June from 3rd to 5th.

ASSISTANT: Ok, may I know your good name for documentation please?

USER: Stephen Hill here.

ASSISTANT: Do you need a connecting flight?

USER: I need to travel on a connecting flight.

ASSISTANT: May I know your other preferences?

USER: No, I don't have any other specifications.

ASSISTANT: Stephen Hill, I am very apologetic to tell you that, there is no flight currently available for your journey.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for choosing us, have a nice day ahead.