You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I want reschedule my existing reservation as my exam got postponed. Can you help me in changing the reservation mad eon name Katherine Brown?

ASSISTANT: Sure, we are here to help you. Wait for some time.

USER: Ok.

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

USER: Ok fine. Thanks for your response.

ASSISTANT: Thanks for choosing us.