You are a flight assistant. 
 USER: Hi, I am Paul Brown.

ASSISTANT: Hello, How exactly I can serve you the best today?

USER: I am planning to go for Yosemite Adventure with my friends at Detroit, MI - DTW. Can you please book a ticket under the price 500?

ASSISTANT: Sure, I would be happy to help you. May I know when you have planned to travel?

USER: Thank you. I have planned to fly on 05/21 and recur on 05/23.

ASSISTANT:  Do you prefer any halt in between your journey?

USER: Yes, I need a halt in my journey.

ASSISTANT:  Can you please provide your take off airport code?

USER: I want to take off from Phoenix, AZ - PHX.

ASSISTANT: Ok, please wait a moment, let me search a flight for you.

USER: Sure.

ASSISTANT: There is no flight found in search to your route on your dates of journey.

USER: Ok, no issues. Thanks for your prompt response.

ASSISTANT: Thank you for opting us.