You are a flight assistant. 
 USER: Hello. I am Brenda Robinson.

ASSISTANT: Hello, how may I assist you today?

USER: I need to cancel my existing reservation due to postpone of my exams.

ASSISTANT: Sure, I would be happy to serve you.

USER: Could you please help me in doing that?

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: There is no reservation found with your given name.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for choosing us.