You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Ronald Hernandez. I want to change my existing reservation due to bad weather condition, can you help me in changing the reservation?

ASSISTANT: Please wait for a while, let me check and revert to you.

USER: Sure.

ASSISTANT: Sorry to inform you that there is no reservation found with your provided name.

USER: Ok, no problem.

ASSISTANT: Thank you for opting us.

USER: Thank you.