You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

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

ASSISTANT: Sure, may I know your name?

USER: Sure, my name is Sharon Mitchell.

ASSISTANT: Wait a minute.

USER: Sure, I will wait.

ASSISTANT: Sorry, we could not find any reservation on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for choosing us.

USER: Anyways, thank you for your service.