You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I am Sandra Mitchell. I have a plan to visit beer festival at Detroit, please book a flight ticket under price 500.

ASSISTANT: Sure, may I know your travel dates?

USER: My travelling dates are from 09/14 to 09/16.

ASSISTANT: Ok, let me know your source and destination airport codes please?

USER: My source code is PHX and Destination code is DTW.

ASSISTANT: Sorry, there are no flights available for given schedule.

USER: No issues, thanks for the information.

ASSISTANT: Thank you for contacting us.