One of the possibles use of ajax technology is to have an automatic update of data in a web page.This is easily possible using the ajaxObject.

First of all, we have to think to an object that is available in the ajaxObject: timerObject.

This is normally used inside ajaxObject for timeout and progress bar, but it can also be used any time a timer is needed.

So, what code to do this?

Firstly let define a new ajaxObject to prepare a request for content.

This has been already discussed in my previous article.

Then we have to create a new timer that will make the request:

The three parameters of timeObject call are:

1. Timing in milliseconds.

2. Function to be executed, in this case is an ajax request

The third optional parameter would be the ID of <span> or <div> where to show a progress bar, but this is not needed since the progress bar will be displayed by the ajaxObject.

Finally we have to activate the timing. This can be done calling:

that can be placed were you need. For example using onload:

This will do the job. Of course, the first call will be done after the timeout expires (in our example 5 seconds) and you might dislike a similar behavior and you might want the first call to be done just after loading the page. If so, just change the body call in the following way:

The code af1.showprogressbar=false; just disable the progress bar, so old content remains until a new one is available.

That’s all folks!

Here is the full HTML code: