Detecting Client System-php

if(isset($_server[' Http_user_agent '])) {        $userAgent=Strtolower($_server[' Http_user_agent ']); $clientkeywords=Array(            ' Nokia ', ' Sony ', ' Ericsson ', ' mot ', ' Samsung ', ' HTC ', ' SGH ', ' lg ', ' sharp ', ' sie-', ' Philips ', ' Panasonic ', ' Alcate L ', ' Lenovo ', ' iphone ', ' ipod ', ' blackberry ', ' Meizu ', ' Android ', ' NetFront ', ' Symbian ', ' UCWeb ', ' WindowsCE ', ' Palm ', ' operamini ', ' Operamobi ', ' opera mobi ', ' Openwave ', ' nexusone ', ' cldc ', ' MIDP ', ' wap ', ' mobile '        ); $upgradekeywords=Array(' iphone ', ' ipod ', ' chrom ', ' Safari '); $operaminikeywords=Array(' Operamini ', ' Opera Mini ', ' opera mobi '); $androidkeywords=Array(' Android '); Echo($userAgent.‘ <br/> ');//Echo (Preg_match ("/(". Implode (' | ', $clientkeywords). ") /i ", $userAgent))//Echo (Strpos ($userAgent, ' ipad ')///////////////Echo (Preg_mat CH ("/(". Implode (' | ', $clientkeywords). ") /i ", $userAgent) &&strpos ($userAgent, ' ipad '));        if(Preg_match("/(".implode(' | ',$clientkeywords).") /I ",$userAgent) &&Strpos($userAgent, ' ipad ') = = =false)        {            if(Preg_match("/(".implode(' | ',$androidkeywords).") /I ",$userAgent)){                Header("Location:http://xxxxx"); Exit; }Else{                Header("Location:http://xxxxx"); Exit; }        }Else{            Header("Location:xxxxxx"); Exit; }    }

Detecting Client System-php