You are a flight assistant. 
 USER: Hello, I am Karen Smith.

ASSISTANT: Hello, how may I serve you today?

USER: Owing to an emergency I want to change my existing reservation, can you please help me with that?

ASSISTANT: Sure, please wait I will get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting, we have not found any reservation with your given name.

USER: Ok, no issues. Thanks for your information.

ASSISTANT: Thank you for choosing us.