11.1. Why Logins Work Well with AJAX
A login is a type of application that fits into an AJAX paradigm well. Logins are forms that need to be submitted, but they generally take up only a small part of a page. On public sites, you might want to log in multiple times, generally in relation to another action that you've already performed, such as filling out a comment form. A login form also needs the ability to show login failure messages and make it easy for the user to type in his or her password again. To sum up, a Web site login is generally a few square inches on a Web site, and it's handy to have the login on every page of a site. Treating it as its own separate entity works well, and using AJAX so that only the login section submits when logging into the site makes for a much nicer user experience. AJAX-based logins are used by many of the Google sites. An example of Google's AJAX login is shown in Figure 11-1.
Figure 11.1. Google's AJAX login