You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Gregory King here.

ASSISTANT: How can I aid you today?

USER: I would like to change my reservation as my exams are postponed to next month, can you please help me in changing?

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you for positive response.

ASSISTANT: Please wait for a minute.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

USER: That's ok, not a problem. Thank you for checking out.

ASSISTANT: Thank you for reaching us.