Even if the
round-trip to the web server is fast, the entire page will ???blink??? as the new data is rendered.
The browser will clear and redraw the entire page, even though most of it doesn??™t
change.
Using AJAX, you can implement a solution that simply displays a visual indicator that
the data is being loaded while it is being retrieved in the background. Although the operation
of retrieving and displaying the data takes about the same amount of time, the
second example provides a much more dynamic look and feel. The user is still in control
while the data is being retrieved. At any time, he can enter the code for a new company
and retrieve its information without waiting for the first company??™s data to be loaded.
AJAX applications typically use HTML, JavaScript, and the associated technologies
DHTML and Cascading Style Sheets (CSS) to build UIs. When the interfaces need to
change dynamically, a call to the server is usually made using the XMLHttpRequest object.
The server returns new HTML markup for the bit of the page that needs to be updated,
which gets inserted into the DOM and re-rendered by the browser.
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