You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Jonathan Jones here.

ASSISTANT: How can I help you?

USER: I want to change my existing reservation due to the climate, hope your helping me on that.

ASSISTANT: Sure, I will help you. No reservation found on your name Jonathan Jones.

USER: Ok, thank you for your information.

ASSISTANT: Thank you for contacting us.

USER: Welcome.