Whether exist in AJAX problems with convenience of use (so we shall translate further the term usability)?

As a result of use of technics{technical equipment} of dynamic updating web-page with the help of the data received through AJAX-interaction and DHTML, appearance of page and its{her} structure can strongly change.

The user can want at any time to press buttons of a browser "Back" or "Forward", to create a bookmark for page, to copy URL pages from line URL of a browser and to share her{it} with the friend through e-mail or a chat, to unpack{print out} page. Therefore at designing AJAX-applications it is necessary for you to think over carefully all that the expected behaviour at navigation, creation of bookmarks, a seal and other actions in a browser would be such as it is described below.

* Navigation (Navigation).

What reaction of your application to buttons of a browser "Back", "Forward", "Refresh", "Bookmark" is expected? You could realize required behaviour independently (manually), but, maybe, it is easier to use JavaScript-environment, such as Dojo which gives API for manipulations with a history of loading of pages in a browser and managements of navigation.

* Creation of bookmarks and manipulations with URL (Bookmarking and URL sharing).

Many users want to create bookmarks or to copy / insert URL in a corresponding line of a browser. Dojo contains API for performance of these of action.

* A seal (Printing).

In some cases the seal of dynamically formed pages can represent complexity.

Other reasons useful to developers, using AJAX:

* Support of a browser (Browser Support).

Not all browsers (and not all their versions) support a full set of functions AJAX/DHTML. Look quirksmode.org with the list of the browsers supporting AJAX, and possible{probable} ways of the decision of problems.

* An interdiction on performance JavaScript.

You should expect, that will take place, if the user will forbid performance JavaScript (there can be some lawful reasons on which support JavaScript and CSS can be disconnected in a web-browser of the user).

* A delay (Latency).

Remember a delay at designing the application. Already working application will respond on searches much faster, than what has just been started on the server but to which yet there were no references{manipulations}. Also remember that if some client searches almost simultaneously have been made, the same order of answers of the server is not guaranteed. More detailed discussion of questions of a delay can be found on a site of the Problem of delays in AJAX: a myth or a reality?

* Accessibilty.

Granting of access to your site to people with the limited opportunities (invalids) not only is welcomed, but also is the requirement of the legislation in many cases at sales. There are some surprising adapting technologies which help people to get access to Web-resources, despite of the limited opportunities of sight, hearing, speech, physical restrictions. Having studied some well documentary techniques and it is a little having reflected, you can make the applications compatible with these technologies of providing of access.

Degradability is the term used for the description of techniques, intended for adaptirovanija applications to a wide range of web-browsers. Many AJAX-libraries have built - in degradability. But if you will create own AJAX-functionality, simply follow the practical recommendations given by the organizations on development{manufacture} of standards, such as World Wide Web Conrsoritum (W3C), to promotion of standards, such as Web Standards-community, and many others. In this case your application can work effectively in browsers which do not support AJAX since even having lost a part of the effective opportunities at performance in such less "capable" browsers, your application will be all the same ready to use.

Remember, that it is not necessary to apply AJAX only for the sake of demonstration of own "steepness". For creation of the application - that people of it{him} used motive. But people not begin to use your application if it is incompatible with their web-browser.