You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Karen Jackson.

ASSISTANT: How may I serve you today?

USER: Owing to an emergency, I want to change my reservation. Can you help me to modify my reservation?

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: We did not find any reservation on your given name in our data.

USER: Ok, thank you.

ASSISTANT: Thank you.