You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What assistance that can I do for you?

USER: I am Jonathan Mitchell. Due to my health problem I want to change my reservation, can you please help me to change my reservation?

ASSISTANT: Yes, please give me a moment.

USER: Sure.

ASSISTANT: I have found your reservation, may I know your airport region codes?

USER: My airport code are IAD to SEA.

ASSISTANT: May I know your preferable dates?

USER: My travelling dates are 09/05 to 09/07.

ASSISTANT: I found a flight with a 1 landing connection in another airport with a fare of 100, can I proceed?

USER: Yes, you can book it.

ASSISTANT: Ok, your ticket is done in 1028 flight and the airlines is AA to your region. Thank you for contacting us, have a nice day.

USER: Thank you for your help.

ASSISTANT: Welcome.