You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Jason Jones here. Due to bad weather, I want to change my existing reservation.

ASSISTANT: Ok, I will help you. Please wait for a while.

USER: Ok.

ASSISTANT: There is no reservation matching with your details.

USER: That's ok. Thank you for your help.

ASSISTANT: Thank you for choosing us.