You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello,. How may I serve you?

USER: I want to attend Science festival with my students at Philadelphia, Can you book a ticket with direct flight?

ASSISTANT: Sure, on which dates you wish to travel?

USER: I want to travel on 03/05 and return on 03/07.

ASSISTANT: Help me with your boarding and landing airport codes?

USER: NY-EWR and PA-PHL are my journey airport codes.

ASSISTANT: Sorry for the inconvenience, there were no flights found with your scheduled dates.

USER: Not a problem, thank you for the information.

ASSISTANT: Thanks for opting us, have a great day.