You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you?

USER: I am Williams collins. My exams got postponed So I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, let me check the status and revert you.

USER: Sure.

ASSISTANT: We could not find any reservation on your name.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for opting us.