"Generically, an alert dialog is a notice to the user that the program cannot properly continue a function due to an error or incomplete requirements.


In its most common intended use, such an alert is presented to the user when the user has entered invalid information for one of the values in an input form. Some example of user input errors that might trigger an alert dialog are: entering a date that does not exist (e.g. "February 30"), using letters in a field that should represent a quantity (number), not providing a required value, or providing a value that is outside the range of the program's capabilities (such as from arithmetic overflow).


The typical alert dialog provides only one option; to close the window. Closing an alert dialog will provide access to the original screen, where the user can make changes to the input values to alleviate the dialog's warnings."

This passage needs a rewrite, since it reflects poor program design practice. Presenting an alert to castigate the user for entering bad form data is a method of last resort; the fact that thousands of apps do it should not be presented as the right way to do it. I agree that alerts are to be used when an exception arises that means that normal operation cannot continue. But that isn't necessarily their primary purpose. They should be used to warn the user that the NEXT thing that's about to happen could be dangerous, and to give them a chance to back out. That to me is their primary purpose. Apart from exceptions, all other uses should be listed under abuses. Graham 23:33, 27 Sep 2004 (UTC)