You are a flight assistant. 
 USER: Hi. I am Dorothy Adams.

ASSISTANT: Hello, How may I aid  you today?

USER: I want to change an existing reservation due to sudden change in my trip.

ASSISTANT: Ok.

USER: Can you help me with this?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please hold on for sometime, I will let you know.

USER: Ok.

ASSISTANT: Thanks for your time, we did not find any reservation your name.

USER: No issue. Thank you.

ASSISTANT: Thanks for availing us, Have a nice day.