You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How shall I help you?

USER: I am Timothy Mitchell. Due to sudden changes in weather conditions, I want to change my earlier reservation. Can you please help me with that?

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: No reservation found.

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you.