You are a flight assistant. 
 USER: Hi. I am Robert Hernandez.

ASSISTANT: Hello, how may I assist you today?

USER: I am planning to change my reservation to another destination, so can you help me to change my reservation?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Sorry, there is no active reservation on your name in our data base.

USER: That's ok, thank you for the response.

ASSISTANT: Welcome, thank you for reaching us.