Devolver el browser con el que el cliente accedió a la página en PHP

Función en PHP que devuelve el nombre del browser con el que el cliente esta accediendo a tu página web

function browser()
{
if((ereg("
    Nav"
, $_SERVER["
    HTTP_USER_AGENT"
])) ||
(ereg("
    Gold"
, $_SERVER["
    HTTP_USER_AGENT"
])) ||
(ereg("
    X11"
, $_SERVER["
    HTTP_USER_AGENT"
])) ||
(ereg("
    Mozilla"
, $_SERVER["
    HTTP_USER_AGENT"
])) ||
(ereg("
    Netscape"
, $_SERVER["
    HTTP_USER_AGENT"
])) AND
(!ereg("
    MSIE"
, $_SERVER["
    HTTP_USER_AGENT"
]) AND
(!ereg("
    Konqueror"
, $_SERVER["
    HTTP_USER_AGENT"
])))) $browser =
"
    Netscape & quot;
    ;
    elseif(ereg("
MSIE"
    ,
    $_SERVER["
    HTTP_USER_AGENT"
])) $browser = "
    MSIE & quot;
    ;
    elseif(ereg("
Lynx"
    , $_SERVER["
    HTTP_USER_AGENT"
])) $browser = "
    Lynx & quot;
    ;
    elseif(ereg("
Opera"
    , $_SERVER["
    HTTP_USER_AGENT"
])) $browser = "
    Opera & quot;
    ;
    elseif(ereg("
Netscape"
    , $_SERVER["
    HTTP_USER_AGENT"
])) $browser = "
    Netscape & quot;
    ;
    elseif(ereg("
Konqueror"
    , $_SERVER["
    HTTP_USER_AGENT"
])) $browser = "
    Konqueror & quot;
    ;
    elseif((eregi("
bot"
    , $_SERVER["
    HTTP_USER_AGENT"
])) || (ereg("
    Google"
, $_SERVER["
    HTTP_USER_AGENT"
])) || (ereg("
    Slurp"
, $_SERVER["
    HTTP_USER_AGENT"
])) || (ereg("
    Scooter"
, $_SERVER["
    HTTP_USER_AGENT"
])) || (eregi("
    Spider"
, $_SERVER["
    HTTP_USER_AGENT"
])) || (eregi("
    Infoseek"
, $_SERVER["
    HTTP_USER_AGENT"
]))) $browser = "
    Bot & quot;
    ;
    else $browser = "
Other & quot;
;
return $browser;
}