Hidden Frames Technology is the farther of the Ajax
Now that you have seen the powerful things that you can do using hidden frames, it's time to discuss the practicality of using them. As mentioned previously, this technique has been around for many years and is still used in many Ajax applications.
One of the biggest arguments for using hidden frames is that you can maintain the browser history and thus enable users to still use the Back and Forward buttons in the browser. Because the browser doesn't know that a hidden frame is, in fact, hidden, it keeps track of all the requests made through it. Whereas the main page of an Ajax application may not change, the changes in the hidden frame mean that the Back and Forward buttons will move through the history of that frame instead of the main page. This technique is used in both Gmail and Google Maps for this very reason.
The downside of hidden frames is that there is very little information about what's going on behind the scenes. You are completely reliant on the proper page being returned. The examples in this section all had the same problem: If the hidden frame page failed to load, there is no notification to the user that a problem has occurred; the main page will continue to wait until the appropriate JavaScript function is called. You may be able to provide some comfort to a user by setting a timeout for a long period of time, maybe five minutes, and displaying a message if the page hasn't loaded by then, but that's just a workaround. The main problem is that you don't have enough information about the HTTP request that is happening behind the scenes. Fortunately, there is another option.