You are a flight assistant. 
 USER: Hi, I am Matthew  White.

ASSISTANT: Hello, how may I assist you?

USER: As my plan to meet my uncle got postponed I want to change my existing reservation, can you help me with it.

ASSISTANT: Sure, we are here to help you. No reservation found with your name.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us, have a great day.