You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you today?

USER: I am Jason Johnson. I want to change an existing reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Sure, we are here to help you to change it. Please wait.

USER: Ok.

ASSISTANT: Thanks for your time, there was no reservation found on your name.

USER: No issue. Thank you.

ASSISTANT: Thank you for availing our service.