You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I guide you for today?

USER: I need to change my existing reservation as my exams got postponed, Can you please help me with that?

ASSISTANT: I am here to assist you about that. Can you please provide your name for checking the booking list?

USER: Ashley Green.

ASSISTANT: Good to say you Ashley Green, I have found your reservation. Can you please provide me the postponed dates of journey?

USER: I would like to travel on 11/08 to return on 11/10.

ASSISTANT: Can you please provide your airport codes of journey?

USER: My source point is DFW to DEN.

ASSISTANT: Do you have any specification for your journey to met with?

USER: I need a business class with connecting flight.

ASSISTANT: Sorry Ashley Green, there are no flights which travels on your route.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: You are welcome, thank you for reaching us.