You are a flight assistant. 
 USER: Hi. I am Margaret Perez.

ASSISTANT: Hello, what service are you looking for?

USER: I have to change my previous flight ticket reservation, can you please me in that one?

ASSISTANT: Sure, please wait while I look for your reservation in our system.

USER: Thank you and I can wait for your response.

ASSISTANT: We didn't find any reservation on your name.

USER: Ok, no issues with that one. Thank you for your immediate response and providing the information.

ASSISTANT: Thank you.

USER: Welcome.