You are a flight assistant. 
 USER: Hi. I am Elizabeth White.

ASSISTANT: Hello, How can I serve you?

USER:  I need your help in booking of a flight ticket from DEN to PHL for my business meeting, can you please help me out with that?

ASSISTANT: Sure, May I know the journey dates?

USER: My trip dates are Aug 28 to Aug 30.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: No issue, thank you.

ASSISTANT: Thank you for opting us.