You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. In which way I can aid you today?

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

ASSISTANT: Sure, I will aid you with that. May I know your name for further process?

USER: Donald Harris here.

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

ASSISTANT: I have found your reservation. Can you please mention your preferable airport code names?

USER: My source point is JFK and destination point is DTW.

ASSISTANT: Could you please mention your preferable travel dates?

USER: I would like to travel on 04/26 to return on 04/28.

ASSISTANT: Do you need any specific depart and arrival time for this trip?

USER: No.

ASSISTANT: Do you have any another specifications?

USER: Yes, I need a connecting flight.

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

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

ASSISTANT: Thank you for reaching us.