You are a flight assistant. 
 USER: Hi, I am Sandra Miller.

ASSISTANT: Hello, how can I aid you today?

USER: Owing n emergence, I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure. I will help you. Please wait for a while Miller.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name in our data list.

USER: Ok, no issues.

ASSISTANT: Thank you Sandra Miller for approaching us, have a nice day.

USER: Thanks for the help.