You are a flight assistant. 
 USER: Hello, I am Kathleen Collins.

ASSISTANT: Hello.

USER: Can you aid me in booking a flight from DEN to LAX?

ASSISTANT: How may I assist you today? Sure, may I know your travelling dates, please?

USER: I want to start on Feb 9th and return back on Feb 11th.

ASSISTANT: Do you need any specifications?

USER: I want to depart in afternoon time.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: No issues. Thank you for checking.

ASSISTANT: Thank you for opting us.

USER: You are welcome.