You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Barbara Wilson. I want to book a flight ticket to attend a business meeting in Philadelphia, so please help me in booking a flight ticket.

ASSISTANT: Ok Wilson, I am here to help you. Please share your complete airport codes.

USER: My source is Detroit, MI - DTW and destination code is PA - PHL.

ASSISTANT: May I know your preferred dates of travelling?

USER: I want to fly on 07/20 and return on 07/22.

ASSISTANT: Ok, give me a while I'll be back with flight details.

USER: Sure.

ASSISTANT: You have no flights on your planned dates.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for approaching us.