You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER:  I want to book a flight ticket  from Denver to Philadelphia.

ASSISTANT: OK. Please provide me your airport code?

USER: My airport codes are  from CO- DEN to PA- PHL? I am Patricia Hernandez.

ASSISTANT: Please also provide me your journey date?

USER:  My journey dates are from Dec/3 to Dec/5. I need 1 connection limit with a price limit - 500.

ASSISTANT: Please wait for a while.

USER: OK.

ASSISTANT: Thanks for your patience. Sorry to inform you, There is no flight on given journey dates.

USER: OK, Thank you for your service.

ASSISTANT: Thank you, Have a nice day.