You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I assist you?

USER: Will you please book me a flight ticket from DTW to OAK?

ASSISTANT: Sure, I am happy to help you. Can you please tell me your journey dates?

USER: I will start on Apr 20th and return on Apr 22nd.

ASSISTANT: Ok, how many connections do you prefer in between your journey?

USER: I need 1 lay by.

ASSISTANT: May I know your name please?

USER: I am Larry Williams.

ASSISTANT: I regret to tell you that, there are no flights found in this route on the dates you have given.

USER: That alright, thanks for the information.

ASSISTANT: Most welcome. Thank you for reaching us.