This post originally appeared on the Yahoo! Accessibility blog.
Practically every web site these days uses some kind of dynamic alerts or dialogs. Typically, messages such as "your settings have been saved", "there was an error loading the content", etc, are called alerts because they require no action from the user (other than clicking the OK button) to dismiss them). Dialogs are message boxes or windows that ask the user to perform an action, e.g. to confirm or cancel something. Dialogs may also offer additional actions such as "never show this again" checkbox.
Alerts and dialogs that are generated by adding or removing HTML nodes in the DOM are called dynamic because their creation does not require full page refresh.
A special attention should be given to making alerts and dialogs accessible for keyboard users and users of screen readers, particularly when your web site is a content-based one.
Following these rules you can make your dynamic alerts and dialogsRead More »from Make Dynamic Alerts And Dialogs Accessible