You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you help me to book a flight from SFO to DTW?

ASSISTANT: Sure, may I know the travelling dates?

USER: My trip dates are Dec 21 and Dec 23 respectively.

ASSISTANT: Do you have any connection limit?

USER: I prefer for a connecting flight to travel.

ASSISTANT: Is there any other requirements?

USER: No other requirements.

ASSISTANT: May I know your name?

USER: Patricia Thomas here.

ASSISTANT: Please wait a minute.

USER: Okay.

ASSISTANT: Sorry, no flights found with your preferable dates.

USER: Thank you for the help.

ASSISTANT: Thank you for opting us.