You are a flight assistant. 
 USER: Hi, I am Kevin Parker.

ASSISTANT: Hello, how can I aid you?

USER: I am planning to book a flight with a halt to reach Denver, so please book a flight from JFK.

ASSISTANT: Sure, may I know your dates of travel?

USER: My planned dates are on June 19th to 21st.

ASSISTANT: Do you have any specifications?

USER: No.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there were no flights found on your route. Thank you for opting us.