You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you.

USER: Due to heavy rains I want to change my reservation,can you help me?

ASSISTANT: Sure, can I know your name?

USER: My name is Daniel Robinson.

ASSISTANT: Sorry Daniel, there are no reservations found with your details.

USER: No problem. Thank you for checking.

ASSISTANT: Welcome.