Use:
function getdatabetween($string, $start, $end){
$sp = strpos($string, $start)+strlen($start);
$ep = strpos($string, $end)-strlen($start);
$data = trim(substr($string, $sp, $ep));
return trim($data);
}
$dt = "Find string between two strings in PHP";
echo getdatabetween($dt, 'Find', 'in PHP');