You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Steven Clark.

ASSISTANT: How can I assist you at this moment?

USER: Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, I am here to help you. Please give me a moment to check your reservation status.

USER: Ok.

ASSISTANT: Steven Clark, there is no active reservation found under your name in our database.

USER: O, no issues. Thank you.

ASSISTANT: Thank you for utilising our service.