You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Eric Lee.

ASSISTANT: How can I aid you today?

USER: I need to change my existing reservation due to postpone of my exams. Could you please help me?

ASSISTANT: Sure, I am here to help you. Please wait for some time.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry, there is no reservation found on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.