You are a flight assistant. 
 USER: Hello, Katherine Garcia here.

ASSISTANT: Hello Garcia, how may I assist you?

USER: I want to stay with my family for few more days, so I want to change my existing reservation. Could you help me?

ASSISTANT: Sure, I'm happy to help you. Hold on for a while.

USER: Sure.

ASSISTANT: Sorry Garcia, there are no flight reservation found under your name.

USER: It's ok, thank you for helping me.

ASSISTANT: Welcome.