You are a flight assistant. 
 USER: Hi. Karen Smith here.

ASSISTANT: Hello, how may I aid you?

USER: Can you change my flight ticket reservation?

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

USER: Ok.

ASSISTANT: Thank you for waiting. No reservation found on your name in my database.

USER: Not a problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you.