You are a flight assistant. 
 USER: Hi, I am David Clark.

ASSISTANT: Hello, how may I serve you?

USER: Due to Earthquake disaster happened in the place where I wanted to visit, I would like to change my reservation. Can you help me with that?

ASSISTANT: Sure, wait a minute please.

USER: Ok.

ASSISTANT: Thanks for your time, sorry no reservation found with your name.

USER: Ok, no issues.

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

USER: Thanks for your prompt service.