You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Mary Lee.

ASSISTANT: How can I assist you at this moment?

USER: Owing to an emergency, I need to change my existing reservation. Can you please help me with that?

ASSISTANT: Sure, I am here to help you. Please give me a moment to check your reservation status.

USER: Ok.

ASSISTANT: Mary Lee, there is no active reservation found under your name in our database.

USER: It's ok, not an issue. Thank you for the information.

ASSISTANT: Thank you for utilising our service.