You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Catherine Garcia. Due to sudden work, I need to change my reservation. Can you please help me with it?

ASSISTANT: Sure, please wait for a moment to check your details.

USER: Ok.

ASSISTANT: No reservation found on your name in my database.

USER: Ok, not an issue. Thank you.

ASSISTANT: Welcome.