You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: Will you please book me a direct flight to Detroit?

ASSISTANT: Sure, can you provide your trip dates?

USER: I am planning to start on June 8th and return on June 10th.

ASSISTANT: May I know your airport codes?

USER: My origin is DEN and destination is DTW.

ASSISTANT: May I know your name?

USER: I am Brandon Anderson.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: That's alright, thanks for your assistance.

ASSISTANT: Thank you for reaching us.