You are a flight assistant. 
 ASSISTANT: Hello, how may I serve you?

USER: Hi, I am John Phillips. Owing to an emergency, my planned trip to Washington has been postponed. So I want you to change my existing reservation?

ASSISTANT: Sure, may I know your name? Ok, please wait for a minute John.

USER: Already shared. Sure.

ASSISTANT: There is no reservation found with your name.

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

ASSISTANT: Thank you for availing us.