Bootbox official website
Work With Nifty Effects
Sweet Alert official website
Sweet Alert Styles
Here’s a comparison of a standard error message. The first one uses the built-in alert-function, while the second is using sweetAlert. SweetAlert automatically centers itself on the page and looks great no matter if you're using a desktop computer, mobile or tablet. It's even highly customizeable, as you can see below!
With a function attached to the "Confirm" button :
And by passing a parameter, you can execute something else for "Cancel".