มีคำสั่งที่บอกว่าเราใช้ window อะไร และ browser อะไรอยู่ไหมครับ

function getbrowser(){ 
$agent = $_SERVER['HTTP_USER_AGENT']; 
if(eregi("Netcaptor", $agent)){ $browser = "Netcaptor"; 
} elseif(eregi("(opera) ([0-9]{1,2}.[0-9]{1,3}){0,1}", $agent, $ver) || eregi("(opera/)([0-9]{1,2}.[0-9]{1,3}){0,1}", $agent, $ver)){ $browser = "Opera $ver[2]"; 
} elseif(eregi("(konqueror)/([0-9]{1,2}.[0-9]{1,3})", $agent, $ver)){ $browser = "Konqueror $ver[2]"; 
} elseif(eregi("(lynx)/([0-9]{1,2}.[0-9]{1,2}.[0-9]{1,2})", $agent, $ver)){ $browser = "Lynx $ver[2]"; 
} elseif(eregi("(msie) ([0-9]{1,2}.[0-9]{1,3})", $agent, $ver)){ $browser = "Internet Explorer $ver[2]"; 
} elseif(eregi("Links", $agent)){ $browser = "Lynx"; 
} elseif(eregi("(Firebird/)([0-9]{1,2}.[0-9]{1,3}){0,1}", $agent, $ver)){ $browser = "Firebird $ver[2]"; 
} elseif(eregi("(Firefox/)([0-9]{1,2}.[0-9]{1,2}.[0-9]{1,2})", $agent, $ver)){ $browser = "FireFox $ver[2]"; 
} elseif(eregi("Mozilla/5",$agent)){$browser = "Netscape 5"; 
} elseif(eregi("Gecko", $agent)){ $browser = "Mozilla"; 
} elseif(eregi("Safari",$agent)){ $browser = "OS-X Safari"; 
} elseif(eregi("(netscape6)/(6.[0-9]{1,3})", $agent, $ver)){ $browser = "Netscape $ver[2]"; 
} elseif(eregi("(Mozilla)/([0-9]{1,2}.[0-9]{1,3})", $agent, $ver)){ $browser = "Netscape $ver[2]"; 
} elseif(eregi("Galeon", $agent)){ $browser = "Galeon"; 
} elseif(eregi("(lynx)/([0-9]{1,2}.[0-9]{1,2}.[0-9]{1,2})", $agent, $ver) ){$browser = "Lynx $ver[2]"; 
} elseif(eregi("Avant Browser", $agent)){ $browser = "Avant"; 
} elseif(eregi("(omniweb/)([0-9]{1,2}.[0-9]{1,3})", $agent, $ver) ){$browser = "OmniWeb $ver[2]"; 
} elseif(eregi("ZyBorg|WebCrawler|Slurp|Googlebot|MuscatFerret|ia_archiver", $agent)){ $browser = "Web indexing robot"; 
} elseif(eregi("(webtv/)([0-9]{1,2}.[0-9]{1,3})", $agent, $ver) ){$browser = "WebTV $ver[2]"; 
} else {$browser = "Unknown";} 
return $browser; 
}