You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you today?

USER: Myself Debra Walker from Oakland. I want to change my travel dates in my previous reservation so can you please help me with that?

ASSISTANT: Sure, we are glad to help you to change it.

USER: Ok, thank you.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for your time, there was no reservation found on your name to change it.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: Thank you for approaching us.