Detecting WebTV

Now it's time to check for the browser using JavaScript. We can do that quite simply:

<SCRIPT LANGUAGE="JavaScript" TYPE="text/javascript">
<!-- 
if(navigator.appName.indexOf("WebTV") != -1)
   document.write("You have WebTV");
else 
   document.write("You're using a normal Web browser"); 
//-->
</SCRIPT>

Now you must decide if you're going to write the page dynamically using JavaScript--based on what browser you find, or just refer the browser to a specific page designed for that particular browser. In the future, I predict that everyone will be using XML for their Web pages, and the browser will receive a subset of the page, or the whole page, depending on the device making the request. A Palm Pilot would get a very small version, WebTV would get a bit more, and a standard Web browser would get the whole thing. Until then, however, you'll have to make the choice ahead of time using standard techniques.

Now we'll show you how to detect the browser using a CGI script written in Perl. We'll detect the browser by looking at its HTTP_USER_AGENT variable. If the browser is a WebTV browser, the user is sent to webtvpage.html; if not, they'll go to otherbrow.html.

#!/usr/local/bin/perl -w

$webTVpage = "/webtvpage.html";
$others = "/otherbrow.html";

if ($ENV{'HTTP_USER_AGENT'} =~ /WebTV/)
{
   $location = $webTVpage;
}

else # all others
{
   $location = $others;
}

print "Location: $location\n\n"; 

Designing for Net Devices
WebTV's Resolution Problem