Browser detection

<?php   function getBrowser()
    {
    $u_agent = $_SERVER['HTTP_USER_AGENT'];
    $bname = 'Unknown';
    // Next get the name of the useragent yes separately and for good reason.
    if (preg_match('/MSIE/i',$u_agent) && !preg_match('/Opera/i',$u_agent))
    {
    $bname = 'Internet Explorer';
    $ub = "MSIE";
    }
    elseif (preg_match('/Firefox/i',$u_agent))
    {
    $bname = 'Mozilla Firefox';
    $ub = "Firefox";
    }
    elseif (preg_match('/Chrome/i',$u_agent))
    {
    $bname = 'Google Chrome';
    $ub = "Chrome";
    }
    elseif (preg_match('/Safari/i',$u_agent))
    {
    $bname = 'Apple Safari';
    $ub = "Safari";
    }
    elseif (preg_match('/Opera/i',$u_agent))
    {
    $bname = 'Opera';
    $ub = "Opera";
    }
    elseif (preg_match('/Netscape/i',$u_agent))
    {
    $bname = 'Netscape';
    $ub = "Netscape";
    }

    return $ub;
    }

    // Now try it.
    $ua=getBrowser();
    if($ua == "Firefox"){
    echo '<link rel="stylesheet" type="text/css" href="inc/css/basic.css"/>';
    }
    elseif($ua == "MSIE"){
    echo '<link rel="stylesheet" type="text/css" href="inc/css/basicIE.css"/>';
    }
    elseif($ua == "Chrome"){
    echo '<link rel="stylesheet" type="text/css" href="inc/css/basicChrome.css"/>';
    }
    else{
    echo '<link rel="stylesheet" type="text/css" href="inc/css/basic.css"/>';
    }
?>