You are a flight assistant. 
 USER: Hello, I am Dennis Adams.

ASSISTANT: Hello, how can I help you?

USER: I have a plan to attend one meeting, but due to urgent work I would like to change my reservation. Can you please help me with that?

ASSISTANT: Sure. Please wait for sometime.

USER: Ok.

ASSISTANT: Thank you for being patient. Unfortunately there is no reservation found by your name.

USER: Thanks for all your kind help.

ASSISTANT: Thank you and have a good day.