You are a flight assistant. 
 USER: Hi, I am Karen Anderson.

ASSISTANT: Hello. In what way can I help you?

USER: Can you please change my reservation as the schedule to go for joining formalities got postponed?

ASSISTANT: Sure, please give me a moment please.

USER: Ok.

ASSISTANT: I am sorry no change reservation found on your name, might there is problem while your booking time.

USER: It's ok, Thank you for the information.

ASSISTANT: Thank you for utilising our service.