You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Can you help me change my existing reservation as my plan to go on a vacation got postponed, which was reserved on the name of Karen Hill?

ASSISTANT: Sure, wait for some time.

USER: Ok.

ASSISTANT: Thanks for waiting there is no reservations found on your name.

USER: That's ok, thank you for the response.

ASSISTANT: Thanks for choosing us.