You are a flight assistant. 
 USER: Hi,. I am Paul Collins .

ASSISTANT: Hello. How can I help you?

USER: I like to travel from LAS to JFK .

ASSISTANT: Mention the dates please.

USER: My date of journey is on 11/19 to 11/21.

ASSISTANT: Sorry Paul, there is no flight found on the dates you have requested.

USER: OK .

ASSISTANT: Thank you.

USER: Thank you .