Algorithms Php

Function rot13($string) {
for($i=0;$i $j=ord($string[$i]);
if ((($j>=ord( "n")) & ($j<=ord( "z"))) | ($j>=ord( "N")) & ($j<=ord( "Z"))) {
$j=$j-13;
}
elseif ((($j>=ord( "a")) & ($j<=ord( "m"))) | ($j>=ord( "A")) & ($j<=ord( "M"))) {
$j=$j+13;
}
$new.=chr($j);
}
return($new);
}
?>