You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Can you please help me to change my existing reservation as I have postponed my trip?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please provide your name.

USER: My name is Sharon Baker.

ASSISTANT: Please wait a minute.

USER: Sure.

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

USER: No problem, thank you for checking it.

ASSISTANT: Thank you for opting us.