Updating the web page

Apart from META's refresh, how can I update the web page due to trigger?

[mckingwan]

Hi again~
Now I'm thinking of my web form on how to do the following:
As there are quotas for timeslot of enrolling functions, now when one of the timeslot is full, I wish to
1.Immediately update the timeslot table (note: in this part I also used the <iframe> tag to do this)
2.Immediately update the options for choosing the timeslot by removing one option away from the option list.

I know that there is a tag called <META>, but this is for updating automatically in a period of time, and what I want is if there is a trigger about the status, I can let the web page change the content.

So how can I do in this part? Also, I've found that there is a new technology called Ajax, but as my page is based on php, will this be also helpful without re-structuring my program?

Thanks so much~

[tumr]

You will have to make use of Ajax in order to mimic a "push" to visitors at arbitrary (i.e., when there is new data) timepoints. My suggestion to you is to take a look at a program such as an AJAX chatroom. The reason is that these are a good model for what you're talking about: a user submits new data, and when this happens, other users need to find out. Looking over that type of source code could be of use.