You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can I have your name to proceed further?

USER: Sure, my name is Carol Rodriguez.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for your valuable time, sorry no reservation found on your name.

USER: Ok, no problem. Thank you for your service.

ASSISTANT: Thank you for opting us.