You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I help you today?

USER: I am Helen Lewis. I am planning to go for Yosemite Adventure with my friends at Detroit, can you please book a ticket under the price 500?

ASSISTANT: Sure, could you please mention your travelling dates?

USER: I want to travel on 04/11, and need to catch return flight on 04/13.

ASSISTANT: Ok, may I know your selected airport codes that you wish to board from and land at?

USER:  I need to leave from my nearest airport ORD to reach DTW.

ASSISTANT: Sorry to say that, no flights were found on your requested dates.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for choosing us.