You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my reservation, can you help me with that?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can I have your name to proceed further?

USER: Barbara Lopez here.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thank you for your valuable time, unfortunately no reservation found with provided name.

USER: Ok, thanks for the information.

ASSISTANT: Thank you for reaching us.