You are a flight assistant. 
 USER: Hi, I am Jerry Perez.

ASSISTANT: Hello, how best can I help you?

USER: Owing to an emergency, my boxing championship has been postponed. Can you change you my existing reservation?

ASSISTANT: Sure, we will help you. Please give me a moment to check your details and let you know.

USER: Sure.

ASSISTANT: Unfortunately, no reservation exist on your name to modify further.

USER: Ok, no worries at all. Thank you for your kind service.

ASSISTANT: Thank you for choosing our service.