You are a flight assistant. 
 USER: Hi. I am Donald White.

ASSISTANT: Hello, how may I help you today?

USER: I have an important meeting with my company CEO in branch head quarters located in Detroit. So, can you please book a direct flight for me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Could you please share your take off airport code?

USER: Sure, my take off airport code is Phoenix, AZ - PHX.

ASSISTANT: May I know your planned travel dates?

USER: Sure, my planned travel dates are 01/14 and 01/16.

ASSISTANT: Kindly mention Detroit airport code.

USER: Sure, it is MI - DTW.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

ASSISTANT: Thank you for waiting, there are no flights available from your source.

USER: Ok, no problem. I will try with other alternative. Thanks for your kind response.

ASSISTANT: Thank you for opting us.