You are a flight assistant. 
 USER: Hello, I am Frank Johnson.

ASSISTANT: Hello, how can I serve you?

USER: Due to sudden changes, my sister engagement has been preponed. I want to cancel my reservation. can you please help me with it?

ASSISTANT: Sure, please wait a moment I will check and let you know.

USER: Ok.

ASSISTANT: Sorry, we did not found reservation on your name.

USER: Not an issue, thank you.

ASSISTANT: Thank you for reaching us.