You are a flight assistant. 
 USER: Hi, I am Christopher Smith.

ASSISTANT: Hello, how can I aid you today?

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

ASSISTANT: Sure, we are here to help you. Wait for some time.

USER: Ok.

ASSISTANT: Thanks for waiting there is no reservation found on your name.

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

ASSISTANT: Thanks for approaching us.