You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you now?

USER: I have planned to change my reservation due to sudden change in my trip, can you aid me?

ASSISTANT: Sure, can I have your  good name please to check your  reservation status?

USER: Patricia Wilson.

ASSISTANT: Ok, please wait a  moment.

USER: Sure.

ASSISTANT: Yes Patricia Wilson, your  reservation has found so  please let me know your planned dates.

USER: My preferred dates are May 25th and May 27th.

ASSISTANT: Ok,  please provide me the airport codes of your locations.

USER: I need to visit ORD from LAS.

ASSISTANT: Do you have any preferences?

USER: I need single connection between my trip.

ASSISTANT: Sorry to inform you that no flight is available to you on your planned dates.

USER: No problem, thank you for searching.

ASSISTANT: Thank you for choosing us.