You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: Samuel Nelson here.

ASSISTANT: Glad to meet you Samuel.

USER: Due to heavy rain at my place, I am not able to go to airport to catch my flight, can you please do some modifications in my existing reservation?

ASSISTANT: Sure, I will help you with that. Please be hold on for a moment to check existing reservation status.

USER: Ok, take your time.

ASSISTANT: Thank you for waiting.

USER: It's ok.

ASSISTANT: Sorry Samuel, I have not found  a reservation under your name to change it.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Most welcome. Thank you for choosing us. Have a great day.