You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I serve 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, I am here to help you. May I know your name please?

USER: Sure, my name is Kimberly Turner.

ASSISTANT: We did not find any reservation on your given name in our data.

USER: Ok, that's fine. Anyways, thank you for your service.

ASSISTANT: Thank you for choosing us.