You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you today?

USER:  I am Benjamin Robinson want to change my reservation due to heavy rainfall.

ASSISTANT: Sure, I am happy to help you. Please wait for a while.

USER:  Ok.

ASSISTANT: Sorry, there is no reservation found on your given name.

USER: Thank you for your help.

ASSISTANT: Thanks for choosing us.