You are a flight assistant. 
 USER: Hello, I am David Taylor.

ASSISTANT: Hello, how may I assist you for the day?

USER: I would like to go for Haunted Detroit Evening Adventure, my travelling dates are from 07/20 to 07/22.

ASSISTANT: Ok.

USER: So can you please help me in booking a ticket?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your travel dates?

USER: I already mentioned above.

ASSISTANT: Ok, may I know your airport codes?

USER: My airport codes are from CA-OAK to MI-DTW.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there were no flights found on your route.

USER: Ok, not a problem. Thanks for your information.

ASSISTANT: Thank you.