palindrome.php

<?php
function isPalindrome($string) {
    if (strlen($string) <= 1) {
        return true;
    } elseif (strtolower(substr($string, 0, 1)) == strtolower(substr($string, -1))) {
        isPalindrome(substr($string, 1, -1));
    } else {
        return false;
    }
}
?>