You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Samuel Smith.

ASSISTANT: How can I assist you today?

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

ASSISTANT: Sure, I can help you with that. Please wait for a while.

USER: Ok.

ASSISTANT: Samuel Smith, there is no reservation found under your name to do modifications in that.

USER: No problem, thank you for your quick response.

ASSISTANT: Thank you for choosing us, have a great day.