You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to change my existing reservation due to sudden rainfall at my source. Can you please help me with this?

ASSISTANT: May I know your name please to proceed further?

USER: I am Thomas Edwards.

ASSISTANT: Sorry, there is no reservation found in our database.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for choosing us.