You are a flight assistant. 
 USER: Hello. I am Sarah Mitchell.

ASSISTANT: Hello, how may I render you?

USER: Can you please change my existing reservation due to postpone of my sports event.

ASSISTANT: Sure, we will help you. Please wait a moment, I will check your reservation status and get back to you.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no active reservation found on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.