You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I need to change my existing reservation as my exams got postponed, Can you please help me with that?

ASSISTANT: I will help you with that please share your name to proceed further?

USER: I am Carolyn Green.

ASSISTANT: Sorry, no reservation found as per your preferences in our database.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for choosing us.