You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you for today?

USER: This side Barbara Miller. I am looking for a flight to DEN on 07/17 to give some some appreciation gifts to the people who done a great job in their performance, so can you book a flight ticket for me?

ASSISTANT: Sure, I will help you. Can you please provide your source point from where you want to start your journey?

USER: Thank you for accepting my request and I would like to start from ATL.

ASSISTANT: Ok, when you want to return back to your source point?

USER: Yes, the return trip is on 07/19 from DEN.

ASSISTANT: Sorry Miller, I can not find any suitable flight which can travel to your destination point on your planned dates of journey.

USER: Ok, I will book the ticket on other dates when I have planned. Thank you for your information.

ASSISTANT: My pleasure to serve you. Thanks a lot for employing our service. Have a safe journey.