You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation. Can you help me for that one?

ASSISTANT: Sure, may I know your name please?

USER: Sure, Linda Phillips here.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: There is reservation found as per your name, please share your recent  airport codes please.

USER: Sure, my new airport codes are ATL and DEN.

ASSISTANT: May I know your planned travelling dates please?

USER: My planned travel dates are 09/04 and 09/06.

ASSISTANT: If you have any other specifications please let me know, I'll check availability according to that?

USER: I am comfortable with direct flight only.

ASSISTANT: Sorry Phillips, there is no flight found as per your travelling dates.