PHP Include id= Issue

[adrwm]

Having a problem with the code below, everytime I try to call a page via ?id=hello (that file would be located in incl/hello.html) it just shows the error page.

<? 
$ext = ".html"; 
$id = "incl/".$id.$ext; 
if (file_exists($id)) 
{ 
include($id); 
} else { 
include("incl/404.html"); 
} 
?>

[halojoy]

<?php
$id = $_GET['id'];

$ext = ".html";
$filename = "incl/".$id.$ext;
if (file_exists($filename))
{
include($filename);
} else {
include("incl/404.html");
}
?> 

somepage.php?id=xxx

to get what value variable 'id' has
we use $_GET['id']

[bradgrafelman]

And for more information on how to use external data (e.g. from the URL or from POST'ed form data), see this manual page: [man]variables.external[/man].