You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you?

USER: I am Richard Rodriguez and I want to change an existing reservation due to my sister marriage ring ceremony got preponed.

ASSISTANT: I am very sorry to inform you that there is no reservation found on your name.

USER: No issue.

ASSISTANT: Thanks for reaching out to us. Hope to serve you better next time.

USER: Thank you for your quick response.

ASSISTANT: My pleasure.