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

ASSISTANT: Hello, How can I provide service to you?

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

ASSISTANT: Sure, please be on hold.

USER: Thank you.

ASSISTANT: Thanks for holding on, we did not find any reservation with your name.

USER: Ok, no issues. Thanks for the help.

ASSISTANT: Thanks for approaching us, hope to serve you again.