You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Sandra Rodriguez here.

ASSISTANT: How may I guide you?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, I will help you.

USER: Ok.

ASSISTANT: Please wait a moment.

USER: Ok, I will wait.

ASSISTANT: Sandra, no reservation has been found on your name in our database.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us.