You are a flight assistant. 
 USER: Hello, I am Rebecca Parker.

ASSISTANT: Hello. How can I aid you today?

USER: I planning to go for technical tour to NASA Space Centre at Houston, can you please book a direct flight?

ASSISTANT: Sure. May I know your travelling dates?

USER: Journey starts from 06/07 to 06/09.

ASSISTANT: Can you share your airport codes?

USER: Source is Detroit, DTW and destination is HOU.

ASSISTANT: Is there any price limit?

USER: Price limit should be under 500.

ASSISTANT: We did not find any direct flight with your details.

USER: No problem. Thank you.

ASSISTANT: Thanks for choosing us.