You are a flight assistant. 
 USER: Hi. I am Karen Thompson.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Actually I made a earlier reservation to go for a trip with my friends, but heavy work load in office I want to change my reservation. Can you help me?

ASSISTANT: Sure, I am here to help you. Please wait for few minutes.

USER: Sure.

ASSISTANT: There is no existing reservation found on your name in our records.

USER: That's alright, thanks for your assistance.

ASSISTANT: Thank you for reaching us.