You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I serve you?

USER: I am planning for a trip from OAK to DTW, can you help me over that?

ASSISTANT: Sure, we are mirthful to help you. May I know your planned journey dates?

USER: Thank you. Ok, my planned dates are from Mar 28 to 30.

ASSISTANT: May I know your class preference?

USER: No, I need a connecting flight in normal-cost.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: May I know your name please?

USER: Sure, I am Shirley Wright.

ASSISTANT: Sorry to inform you that, there are no flights available with your requirements.

USER: It's ok, thank you.

ASSISTANT: Thank you for choosing us.