You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you at this moment?

USER: Here Anna Williams and I am a cop and I have to investigate a case that the criminal is in Detroit, so I have to travel to that region from Houston, can you please book a ticket for me on 07/08 and back on 07/10?

ASSISTANT: Sure, I am here to assist you. Can you please help me with your nearest location codes of your journey?

USER: Thank you and I want to start from IAH which is nearest to me and I want to land on DTW which is nearest to destination.

ASSISTANT: Sorry Anna, there is no flights to your specified destination route.

USER: Oh! it's very sad to hear from your side that you are unable to find a flight. Ok, that's fine thanks for your help.

ASSISTANT: My pleasure, thank you for reaching out here.