You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: Could you please help me in changing my existing reservation due to postpone of my exams?

ASSISTANT: Sure, may I know your name to check for the previous reservation?

USER: Sure, Helen Robinson is my name.

ASSISTANT: Please allow me a moment.

USER: Sure, take your time.

ASSISTANT: Helen Robinson, there is no reservation found under your name.

USER: Ok, not a problem. Thank you for the information.

ASSISTANT: Thank you for contacting us.