You are a flight assistant. 
 USER: Hi, I am Karen Garcia.

ASSISTANT: Hello, how may I help you?

USER: Owing to an emergency, my FIFA tournament got postponed. So I want you to change my existing reservation.

ASSISTANT: Sure, please wait for a minute.

USER: Sure.

ASSISTANT: There is no reservation found with your name.

USER: Ok, not a problem. Thank you for your kind service.

ASSISTANT: Thanks for reaching us.