You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you at this moment?

USER: I need to book a flight from PHL to ORD, can you help me with that?

ASSISTANT: Sure, I will help you with that. Can I have your travel dates please?

USER: My trip dates are 07/12 and 07/14.

ASSISTANT: Ok, please let me know the preferable timings of your journey.

USER: I am ok with any timings.

ASSISTANT: Do you prefer any specific class to travel?

USER: I need a connecting flight in business class.

ASSISTANT: Can I have your good name please to proceed further?

USER: I am Mary Mitchell.

ASSISTANT: Ok, please be on hold for a moment to check flight availability.

USER: Sure.

ASSISTANT: Sorry Mary Mitchell, there is no flight is available to you on your dates in business class.

USER: That's ok. Thank you for reaching us.

ASSISTANT: Thank you for choosing us, have a good day.