You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: Brenda Thomas here.

ASSISTANT: How may I help you?

USER: Due to sudden work, I need to change my reservation. Can you please help me with it?

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: No reservation found.

USER: Not an issue, thank you.

ASSISTANT: Thanks.