Create
alternate versions to support multiple browsers
If you want to use new Web technologies,
such as layers, frames, or JavaScript, and you also want
your site to be accessible to people who use lower level
browsers and old screen readers, then you will need to
create an alternate version of your site. The alternate
version should be produced without relying on frames.
Make
use of browser sniffers
Use a browser sniffer to determine which
site version should be sent to each user. Sniffers use a
scripting language like JavaScript or CGI to determine
various aspects about the user's browser, such as its
version, level of JavaScript, browser name, ability to
interpret Java, installed plugins, etc. The example HTML
file below will load one of three HTML pages when the link
is clicked. It determines which page to load based on the
version of JavaScript supported on the browser.
<html><head><title>JavaScript Browser
Sniffer</title></head>
<!-- Find out what level of JavaScript they support. -->
<!-- 10 is for Navigator 2.0 and Internet Explorer 3.0 -->
<!-- 11 is for Navigator 3.0 and Internet Explorer 4.0 -->
<!-- 12 is for Communicator 4.0 -->
<script language="JavaScript">
<!--
ver = 10;
//-->
</script>
<script language="JavaScript1.1">
<!--
ver = 11;
//-->
</script>
<script language="JavaScript1.2">
<!--
ver = 12;
//-->
</script>
<script language="JavaScript">
<!--
function nextPage()
{
//
// If the browser is one of the 4.0 browsers we will use
latestver.html
// Otherwise we will see if they have JavaScript 1.1
before using newver.html
// Defaulting to oldver.html for everyone else.
//
if (navigator.userAgent.indexOf("4.0") >= 0) {
window.location = "latestver.html";
} else if (ver >= 11) {
window.location = "newver.html";
} else {
window.location = "oldver.html";
}
}
// -->
</script>
<body>
<!-- Place oldver.html on the anchor for those browsers
without JavaScript -->
<a href="oldver.html" onClick="nextPage(); return false;">my
link text</a>
</body>
</html>