一个浏览器检查类

<?php
//原作者：epsilon7
//SonyMusic(sonymusic@163.net)
class BrowserDetector  {
    var $UA =  "";    //$HTTP_USER_AGENT的内容
    var $BROWSER=  "Unknown";    //浏览器类型
    var $PLATFORM   =  "Unknown";    //操作系统
    var $VERSION=  "";    //浏览器版本号
    var $MAJORVER   =  "";    //浏览器主版本号
    var $MINORVER   =  "";    //浏览器副版本号
    /* 构造函数开始 */
    function BrowserDetector(){  
        $this->UA   =  getenv(HTTP_USER_AGENT);   
        $preparens  =  "";   
        $parens =  "";   
        $i = strpos($this->UA,"(");   
        if ($i >= 0)   {  
            $preparens  = trim(substr($this->UA,0,$i));  
            $parens = substr($this->UA,$i+1,strlen($this->UA));  
            $j = strpos($parens,")");  
            if($j>=0)  {  
                $parens = substr($parens,0,$j);  
            }   
        }   
        else   {  
            $preparens = $this->UA;   
        }   
        $browVer =  $preparens;   
        $token  =  trim(strtok($parens,";"));   
        while($token)   {  
            if($token=="compatible")  {
            }  
            elseif(preg_match("/MSIE/i","$token"))  {  
                $browVer = $token;  
            }  
            elseif(preg_match("/Opera/i","$token"))  {  
                $browVer = $token;  
            }  
        &n