Delete input with value in (confirmation?)

I just got across this thread:

Allowing the user to add input fields

As I am in similar situation I would like to ask from UX perspective, what happens when the user clicks 4 times to add field and then he enters some value and press delete on filled input. Does it just delete or is there any confirmation? Are there any real-life examples in programs to see this in action and how other companies have done this?