function is_mobile(){
$useragents = array(
'iPhone',
'iPod',
'Android',
'dream',
'CUPCAKE',
'blackberry9500',
'blackberry9530',
'blackberry9520',
'blackberry9550',
'blackberry9800',
'webOS',
'incognito',
'webmate'
);
$pattern = '/'.implode('|', $useragents).'/i';
return preg_match($pattern, $_SERVER['HTTP_USER_AGENT']);
}