I'm back!
@Loco.M
You can see a working demo at my own website if you'll like
www.perditionpoetry.com.
But the site itself will not be completed untill september, just in time for Left 4 Dead, great new game from Valve and Turtle Rock, with zombie and much more

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Then don't troll it too much

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@dannykilla
To restrict specific browser like IE 6, you can download the browser first (or
IE Net Render if you'r using firefox 3.0), than create a clean *.php page, upload it in your website tests directory.
In the file (within <body></body> of the basic HTML code)write:
PHP Code:
<?php
$browser = $_SERVER['HTTP_USER_AGENT'];
echo "$browser";
?>
Than you'll see the possible specific keyword fo the browser you'r using.
IE 6 is "MSIE 6.0", anyway if you'll like to reject more than 2 browser (more than two IE version for example, and sending people to download the last version) modifing the script is really simple, just ask and I'll help you.
@Diffidents

The above one is an example of a possible utility for the addon, how to use it's all about you.
On my side,
I thought this addong while creating a restricted gaming community for my friends, I'm a nerd gamer.
There is no incompatibility issues to avoid, i know how to solve them if i need to, if you are a commercial developer you should use it with real care, as others said kicking people from the site is not usually a commercial benefit, in my side I'm not interested in making money, but in choosing who I'm going to play with, so i can kick people from my site, and be selective.
In specific, the reason i want to reject other browser is also to force people using firefox, or browser different from IE or safari, and this is a my personal battle. I'm not going to explain the reason here because it's not the right place to, it's a my personal choise, and my personal ideals.
Second, as i said not allowing IE i make too young or non nerd users harder to join my community, and that is my target. (I'm not saying that IE is a browser for child or casual users at all. don't misunderstand!)
I'm not surprised if you'll find it silly or useless, it's was invented mainly just for some zealots of hardcore gaming and firefox supported, and even if just 2 people installed it, and maybe there will not be many more, this already make me happy, since this is also my first release. After 2 weeks i bought vb.
I hope to have answered all your question

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