You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation, as my my exams have postponed suddenly. Can you please help me with this?

ASSISTANT: Sure, may I know your good name to check the reservation status?

USER: I am Mary Adams.

ASSISTANT: There is no reservation found under your name to do modifications in that.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.