You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I am Frank Lopez. I want to change my reservation, you help me with the modify my reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: Ok, thank you for informing.

ASSISTANT: Thank you for reaching us.