Mine

<?php
$string = 'wankdadjfaldjfl<blah>djfadlkjfaldfjaldjflaj</blah>dljflajdfljadfjakl';
$start = strpos($string, '<blah>');
$stop = strpos($string,'</blah>');
$length = $stop - $start;
$starts = $start + 6;
$lengths = $length - 6;
$final = substr($string, $starts, $lengths);
echo $final;
?>