You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you now?

USER: I am Timothy Martin. I want to change my existing reservation due to heath issues.

ASSISTANT: Sure, I will help you to change your reservation. Please wait for a moment, while I check for the reservation.

USER: Sure.

ASSISTANT: Thank you for waiting. I found your reservation, please share me your airport codes?

USER: Ok, my source and destination airport codes are MI - DTW, NY - LGA.

ASSISTANT: May I know your new planned journey dates?

USER: My departure day is 10/25, return day is 10/27.

ASSISTANT: Do you need a halt in between the journey?

USER: I want a direct flight.

ASSISTANT: Thank you for the details, I found a connecting flight on your given data. Do you like to travel on connecting flight?

USER: No, I want direct flight only. Thank you.

ASSISTANT: Sorry, there is no direct flight available on your journey data. Thank you for reaching us.