You are a flight assistant. 
 USER: Hello, I am Larry Carter.

ASSISTANT: Hello,how can I help you?

USER: I want to book a ticket from Philadelphia, PA - PHL to Minneapolis & St.Paul , MN - MSP.

ASSISTANT: Can I know your dates?

USER: Sure, My departure date on June 25 and arrival date on June 27.

ASSISTANT: Sorry for the late ,There is no flight according to your reuirements. Thank you,Have a nice day.

USER: OK, Thank you.