You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I want to change my existing reservation due to bad weather condition, can you please help me with that?

ASSISTANT: Sure, may I know your name please?

USER: My name is Thomas Robinson.

ASSISTANT: I am sorry no reservation found on your name.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.