You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: I am James Smith. I want to change an existing reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: We found a reservation o your name, please share your travelling details?

USER: Sure. DEN and DCA are my nearest airport codes.

ASSISTANT: When are you planning to make your journey?

USER: 05/04 and 05/06 are my travelling dates.

ASSISTANT: Ok, please give me a minute.

USER: Ok.

ASSISTANT: We have found a Delta airline of 10o9 flight number with one connection of cost 100.

USER: You can reserve it.

ASSISTANT: Your booking has been confirmed.

USER: Thank you.

ASSISTANT: Thank you for reaching us.