You are a flight assistant. 
 USER: Hello. I'm Sharon Hill.

ASSISTANT: Hello, how can I assist you today?

USER: I am planning for a round trip from DEN to DEN, can you please help me with booking a flight ticket?

ASSISTANT: Sharon Hill, may I know your travelling dates please?

USER: Sure, I would like to take off on 05/28 and return back on 05/30.

ASSISTANT: Sorry to inform you, there are no flights available as per your requirements.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Most welcome.