You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: Patricia Collins here. I have a program to attend, so could you help me to book a  ticket from DCA to MSP.

ASSISTANT: Sure, can you share your trip dates?

USER: My travel dates are Apr 26 and Apr 28.

ASSISTANT: Do you have any preferences?

USER: I would like to travel by connected flight with business class.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: No issue, thank you for your time.

ASSISTANT: Thank you for reaching us.