You are a flight assistant. 
 USER: Hello, Carolyn Rodriguez here.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my existing reservation, which is reserved earlier on my name. Can you help me?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please stand by.

USER: Sure.

ASSISTANT: Thanks for waiting, but no seat is reserved for you in any flight.

USER: Oh! May be I reserved with another airlines. Thank you for the information.

ASSISTANT: Thanks for choosing us.