Confirm & Alert

Confirm and alert are existing since the beginning of Javascript. Due the last versions of APEX the functionality was enhanced, especially with the new integrated alert and confirm actions in APEX 21.2. But what does it mean and what do we have to change? Is it now possible to use alert and confirm in a well looking format without any custom code? What about the APEX JavaScript API changes for these functions? Does the JavaScript Callback mechanique has any impact on this change? Even if you think it’s a no brainer, there are some useful hints how to use this changed feature.