function getBrowser($agent) { 
 $browser = array( 
  "MSIE 5.0" => "/msie 5.0[0-9]*/", 
  "MSIE 5.5" => "/msie 5.5[0-9]*/", 
  "MSIE 6.0" => "/msie 6.0[0-9]*/", 
  "MSIE 7.0" => "/msie 7.0[0-9]*/", 
  "MSIE 8.0" => "/msie 8.0[0-9]*/", 
  "MSIE 9.0" => "/msie 9.0[0-9]*/", 
  "Chrome" => "/chrome\/*/", 
  "FireFox" => "/firefox\/*/", 
  "Netscape" => "/x11/", 
  "Opera" => "/opera*/", 
  "Safari" => "/safari\/*/", 
  "Android" => "/android/", 
  "Mobile Safari" => "/mobile\/[0-9a-z]* safari/", 
  "Robot" => "/yahoo/", 
  "Robot" => "/bot/" 
 ); 
 $agent = strtolower($agent); 
 foreach($browser as $name=>$exp){ 
  if(preg_match($exp, $agent)){ 
  $browser = $name; 
  } 
 } 
 return $browser; 
} 

$u_agent = $_SERVER['HTTP_USER_AGENT']; 
$browser =  getBrowser($u_agent); 
if($browser == 'Android' || $browser == 'Mobile Safari'){ 
 if($browser == 'Android'){ 
  ECHO "ANDROID"; 
 }else{ 
  ECHO "IPHONE"; 
 } 
}else{ 
 ECHO "OTHER"; 
}