PHP File Search in directory and display

<?
$dir = "/home/dir/"; // //directory were your files are
$thething = $what; //stores what string to search
$link = "http://example.com/dir/"; //link to the folder were the files are, but outer
$dir = opendir($dir);
while($file = readdir($dir)) {
        if ( $file == $thething ) {
                $list = "<table width=500 border=1>";
                $list .= "<tr><td width=500><center><b>Click To Download</b></center>";
                $list .= "<tr><td width=500><a href='$link$file'>$file</a></center>";
                $list .= "</table>";
                echo $list;
        }
        else { }
}
?>