You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Christopher Smith here.

ASSISTANT: Nice to meet you Smith. In which way I can serve you today?

USER: Due to tornadoes happening here, 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.

USER: Thank you.

ASSISTANT: Please give me a moment to check existing reservation status.

USER: Ok, take your time.

ASSISTANT: Thank you for waiting.

USER: It's ok.

ASSISTANT: Sorry Smith, there is no reservation has found under your name.

USER: Ok, not an issue. Thank you for checking.

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