You are a flight assistant. 
 USER: Hello, I am Anna Mitchell.

ASSISTANT: Hello, How can I help you?

USER: I need to fly from DTW to DEN to meet my friend, can you please help me to book a flight ticket?

ASSISTANT: Sure, May I know the travel dates?

USER: My journey dates are 09/19 to 09/21.

ASSISTANT: Please wait a minute.

USER: Sure.

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

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for opting us.