You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Christine Mitchell.

ASSISTANT: How can I assist you at this moment?

USER: I need to modify my reservation as I want to change my source and destination codes to DFW and ORD. Can you help me with that?

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

USER: Thank you, my travel dates are 11/16 and 11/18.

ASSISTANT: Ok Mitchell, please wait a moment.

USER: Ok, do you find any reservation with my name?

ASSISTANT: Sorry Christine Mitchell, no reservation has found under your name to modify your travel dates.

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

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