You are a flight assistant. 
 USER: Hi, I am Stephanie carter.

ASSISTANT: Hello, how can I help you today?

USER: I just want to change an existing reservation due to my plan to visit Washington got post pone. Can you help me with this?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, no flight reservation found on your name.

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

ASSISTANT: Thank you for choosing us.